Approach to the infant or child with nausea and vomiting

INTRODUCTION — Nausea and vomiting are common sequelae of a multitude of disorders that can range from mild, self-limited illnesses to severe, life-threatening conditions. The symptoms may be caused by many pathologic states involving several systems (including gastrointestinal, neurologic, endocrine, renal, and psychiatric). Younger children may not be able to describe nausea, which may further complicate diagnosis. The diagnostic process is guided by the medical history and clinical features of specific disorders and their relative frequency among children in different age groups.

Vomiting and nausea may occur together or separately and may not be perceived at the same level of intensity. As an example, vomiting can occur without preceding nausea in individuals with mass lesions in the brain or increased intracranial pressure (ICP). Furthermore, some medications may alleviate vomiting but not the accompanying nausea.

This topic review will provide an overview of the causes of nausea and vomiting and a general approach to diagnosis and management. Individual disorders are discussed in further detail in linked topic reviews. These include several gastrointestinal disorders that present with both abdominal pain and nausea or vomiting. Evaluation of the child in whom abdominal pain is the primary presenting complaint is discussed separately. (See "Emergency evaluation of the child with acute abdominal pain" and "Chronic abdominal pain in children and adolescents: Approach to the evaluation".)

DEFINITIONS

●Vomiting (emesis) refers to the forceful oral expulsion of gastric contents associated with coordinated contraction of the abdominal and chest wall musculature. Vomitus often has a slight yellow tinge, which is caused by reflux of small amounts of bile into the stomach. Vomitus is considered bilious if it has a green or bright yellow color, indicating larger amounts of bile in the stomach; bilious vomiting is often associated with intestinal obstruction, as described below.

●Nausea generally refers to an unmistakable sensation of unpleasantness that may precede vomiting but may be present even in a child who does not vomit. It is often associated with autonomic changes such as salivation, increased heart and respiratory rates, and a reduction in gastric tone and mucosal blood flow [1].

The related terms regurgitation, anorexia, sitophobia, early satiety, retching, and rumination are defined in the table (table 1).

PHYSIOLOGY OF EMESIS

●Neurophysiology – Vomiting may have a physiologic benefit since it provides a means to expel potential toxins. Nausea and vomiting may also induce a conditioned aversion to ingested toxins [2]. In disease states, however, vomiting pathways are activated inappropriately. The major pathways through which nausea and vomiting are induced are vagal afferents, the area postrema, the vestibular system, and the amygdala [1]. Five principal neurotransmitter receptors mediate vomiting: muscarinic (M1), dopamine (D2), histamine (H1), serotonin (5-hydroxytryptamine 3 [5-HT₃]), and substance P (neurokinin 1 [NK1]). (See "Characteristics of antiemetic drugs".)

•Vagal afferent pathway – Abdominal vagal afferents are involved in the emetic response. These pathways can be evoked by either mechanical or chemosensory sensations. Examples of sensations that trigger this pathway include overdistension, food poisoning, mucosal irritation, cytotoxic drugs, and radiation [2]. Vagal afferents are an important site of action of 5-HT₃ receptor antagonists used as antiemetic drugs [1].

•Area postrema – The area postrema has been referred to as the "chemoreceptor trigger zone." Anatomically, this region is located at the caudal extremity of the floor of the fourth ventricle. Because the area postrema represents a relatively permeable blood-brain barrier region, it is the place where many, but not all, systemic chemicals act to induce emesis [1]. The area postrema is an important site for M1, D2, 5-HT₃, and NK1 receptors, each of which is a key mediator of vomiting.

•Vestibular system – The vestibular system is involved in the emetic response to motion. This response is often exacerbated when vestibular input is in conflict with visual sensations [2]. Irritation or labyrinthine inflammation can produce vomiting. Others have suggested that overstimulation of the vestibular system is not a complete explanation for motion sickness and that circulating neuroactive compounds may be involved. H1 receptors in the vestibular nucleus have a role in this response.

•Amygdala – The amygdala is involved in a variety of stress and emotional responses. Among other structures, it receives input from the olfactory bulb and olfactory cortex and sends impulses to the hypothalamus. Aberrant activation of the amygdala may lead to a sensation of nausea.

●Somatomotor events – The act of vomiting represents a highly coordinated sequence of events. As noted above, vomiting describes the act of emptying out the stomach, characterized by cycles of retching followed by the forceful expulsion of gastric contents. The detailed sequence of events is as follows [1]:

•The diaphragm descends and the intercostal muscles contract while the glottis is closed

•The abdominal muscles contract and the gastric contents are forced into the upper gastric vault and lower esophagus

•The abdominal muscle relaxes and the esophageal refluxate empties back into the gastric vault

•Several cycles of retching, each more rhythmical and forceful in nature, occur, with shorter intervals in between

•Abdominal contraction associated with elevation of diaphragm results in forceful expulsion of gastric contents

CLINICAL APPROACH — Patients with acute vomiting, typically for hours to a few days, most often present to an emergency department, whereas patients with chronic symptoms are more often initially evaluated in outpatient office settings. In both urgent care and routine outpatient settings, the following steps should generally be undertaken in patients with nausea and vomiting:

●Identify concerning signs and symptoms that suggest a serious cause of vomiting that requires urgent treatment (table 2). For example, emergency department clinicians should expeditiously exclude life-threatening disorders such as bowel obstruction, diabetic ketoacidosis, adrenal crisis, toxic ingestion, or increased intracranial pressure (ICP). (See 'Concerning signs' below.)

●Determine the etiology if possible. The differential diagnosis is determined, in part, by the child's age and whether the nausea and vomiting are acute, chronic, or episodic.

●Treat as appropriate for the cause and severity of vomiting:

•Identify and correct the consequences or complications of nausea and vomiting (eg, fluid depletion, hypokalemia, and metabolic alkalosis)

•Provide targeted therapy when possible, such as nonoperative reduction for intussusception, surgery for bowel obstruction or appendicitis, or insulin for diabetic ketoacidosis

•Provide supportive care and treatment to relieve symptoms (see 'Treatment' below)

EVALUATION — A careful history and physical examination should be performed. In many cases, the cause of the nausea and vomiting can be determined from the history and physical examination and additional testing is not required. The urgency of pursuing a diagnostic evaluation depends on the duration of illness, overall clinical status of the patient (especially hydration, circulatory, and neurologic status), and associated findings.

Concerning signs — Warning signs that may indicate a serious cause of vomiting include (table 2):

●Nonspecific:

•Prolonged vomiting

•Profound lethargy

•Significant weight loss

●Gastrointestinal obstruction or disease:

•Bilious vomiting

•Projectile vomiting in a young infant <12 weeks of age

•Hematemesis

•Hematochezia (rectal bleeding)

•Marked abdominal distension and tenderness

●Neurologic or systemic disease:

•Bulging fontanelle in a neonate or young infant

•Headache, positional triggers for vomiting or vomiting on awakening, and/or lack of nausea

•Altered consciousness, seizures, or focal neurologic abnormalities

•History of head trauma

•Hypotension disproportionate to the apparent illness and/or hyponatremia and hyperkalemia

Patients should be referred to an appropriate specialist (eg, pediatric gastroenterologist, pediatric surgeon, neurologist) depending on the suspected cause. As an example, immediate pediatric surgical consultation is warranted if appendicitis, bowel obstruction, or bowel perforation are suspected.

History — The history should detail the onset and pattern of the vomiting or nausea (acute, chronic, or episodic), associated symptoms, recent exposures to contacts with similar symptoms, and the possibility of ingestion of medications or toxic substances.

The following clinical features are especially important (table 3):

●Nature of vomiting

•Bilious (green or bright yellow) vomiting suggests intestinal obstruction, especially in a neonate (eg, due to intestinal atresia or volvulus) [3]. (See 'Intestinal obstruction' below and 'Intussusception' below.)

•Projectile (very forceful) nonbilious vomiting in an infant <12 weeks of age suggests pyloric stenosis. (See 'Pyloric stenosis' below.)

•Bloody vomiting (hematemesis) suggests bleeding from esophageal varices if severe. Hematemesis also may be caused by esophageal injury from recurrent vomiting (Mallory-Weiss tear) or by mucosal injury from erosive esophagitis, gastritis, or peptic ulcer. (See "Mallory-Weiss syndrome" and "Approach to upper gastrointestinal bleeding in children", section on 'Etiology'.)

•Acute, recent onset of vomiting, especially with diarrhea and/or fever, suggests an infectious gastroenteritis. (See 'Gastroenteritis' below.)

•Onset after infectious illness suggests postinfectious gastroparesis.

•Recurrent or periodic episodes of vomiting suggest inborn errors of metabolism (especially in a newborn or young infant), cyclic vomiting syndrome, or cannabis hyperemesis syndrome. (See 'Inborn errors of metabolism' below and 'Cyclic vomiting syndrome' below.)

•Early morning nausea or vomiting suggests pregnancy, increased intracranial pressure (ICP), or cyclic vomiting syndrome. (See 'Intracranial hypertension' below.)

•Prolonged vomiting (eg, >12 hours in a neonate, >24 hours in children younger than two years, and >48 hours in older children) suggests a cause that may require intervention, such as obstruction, metabolic disorder, or cyclic vomiting syndrome. In addition, patients with prolonged vomiting are at risk for developing dehydration and electrolyte abnormalities.

•Lack of associated nausea and positional triggers for vomiting suggest increased ICP (especially with headache). (See 'Intracranial hypertension' below.)

●Associated symptoms

•Diarrhea (with or without fever) in a patient with acute onset of vomiting is consistent with viral gastroenteritis. This possibility is supported by a history of close contacts with vomiting and/or diarrhea and suggests gastroenteritis. However, more serious causes of these symptoms should be considered in patients with atypical features. These causes include infection (sepsis, infectious enteritis/colitis), appendicitis, inflammatory bowel disease (IBD), and Hirschsprung disease-associated enterocolitis (especially in neonates or infants with predisposition, such as trisomy 21). (See 'Gastroenteritis' below.)

•Rectal bleeding (hematochezia) suggests intussusception (especially in infants and toddlers), infectious colitis, or IBD. (See 'Intussusception' below and 'Inflammatory bowel disease' below.)

•Fever is associated with many causes of nausea and vomiting, including viral gastroenteritis, appendicitis, streptococcal pharyngitis, urinary tract infection, and, sometimes, IBD. (See 'Gastroenteritis' below and 'Appendicitis' below and 'Other infections' below and 'Inflammatory bowel disease' below.)

•A history of chronic or recurrent infections raises the possibility of an immunodeficiency. Recurrent pneumonia in an infant also may be caused by a tracheoesophageal fistula. (See "Approach to the child with recurrent infections".)

•Prominent headache associated with nausea can be consistent with either migraine or increased ICP. (See 'Migraine' below and 'Intracranial hypertension' below.)

●Medical history – Underlying disorders may provide clues to the cause of vomiting:

•Congenital anomalies or diseases – Consider anatomic, motility, or immunologic causes of vomiting

•Developmental delay – Raises the possibility of undiagnosed metabolic disorder or syndrome

•Neurologic symptoms or disorders – Consider central nervous system lesions or dysmotility

Physical examination — The physical examination should include (table 3):

●Abdominal examination

•Signs suggestive of intestinal obstruction include marked abdominal distension, visible bowel loops, absent bowel sounds or increased high-pitched bowel sounds ("borborygmi"), severe abdominal pain, or vomitus that is bilious (green or yellow) or feculent (with the odor of feces). By contrast, milder abdominal distension and active bowel sounds with normal pitch are common in simple gastroenteritis. (See 'Intestinal obstruction' below and 'Intussusception' below.)

•Focal abdominal tenderness in the right lower quadrant suggests appendicitis or Crohn disease. Focal tenderness in the right upper quadrant suggests gallbladder disease (cholelithiasis or cholecystitis) or pancreatitis. Tenderness in the costovertebral angle suggests pyelonephritis. Abdominal pain or tenderness in the epigastric area is nonspecific but is also consistent with esophagitis, gastritis, peptic ulcer disease, or pancreatitis. (See 'Appendicitis' below and 'Inflammatory bowel disease' below.)

•Hepatomegaly, splenomegaly, or jaundice may be caused by hepatitis, viral infection, or metabolic disorders. (See 'Inborn errors of metabolism' below.)

●Neurologic examination

•Altered consciousness, seizures, or focal neurologic abnormalities may be caused by toxic ingestion, diabetic ketoacidosis, central nervous system mass, or inborn error of metabolism.

•Bulging fontanelle in a neonate or young infant suggests the possibility of hydrocephalus or meningitis.

•Ataxia, dizziness, or nystagmus (eye twitching) suggest vestibular neuronitis or acute cerebellar ataxia. (See "Evaluation of dizziness and vertigo in children and adolescents" and "Acute cerebellar ataxia in children".)

●Other findings

•Atypical ("ambiguous") genitalia in an infant and/or hyperkalemia suggest the possibility of adrenal insufficiency (usually due to congenital adrenal hyperplasia). (See 'Adrenal insufficiency' below.)

•An unusual odor emanating from the patient, especially in infants and toddlers, should prompt an investigation for metabolic causes of vomiting. (See 'Inborn errors of metabolism' below and "Inborn errors of metabolism: Epidemiology, pathogenesis, and clinical features", section on 'Abnormal odors'.)

•Enlarged parotid glands in an adolescent should raise suspicion for bulimia. (See 'Bulimia' below.)

Laboratory testing — For patients with vomiting that is severe, prolonged (eg, >12 hours in a neonate, >24 hours in children younger than two years, and >48 hours in older children), or unexplained, screening laboratory tests should include:

●Complete blood count

●Electrolytes, glucose, blood urea nitrogen

●Alanine aminotransferase, aspartate aminotransferase

●Amylase, lipase

●Urinalysis

Additional laboratory testing and imaging should be tailored to the differential diagnosis of the symptoms, based on the history and physical examination (table 4). For patients with fever, urinary symptoms, or diarrhea, the evaluation may include urine culture and stool studies for occult blood, bacterial pathogens, and parasites.

DISORDERS PRIMARILY SEEN IN NEONATES AND YOUNG INFANTS — Gastroesophageal reflux (GER) is common and inconsequential in otherwise healthy infants. The symptom may be described as vomiting by parents/caregivers but is physiologic and gradually improves in most infants during the first year of life [4]. (See "Gastroesophageal reflux in infants".)

By contrast, forceful and repeated vomiting in infants is not normal and should be taken seriously, particularly if there are other signs of illness (eg, fever, weight loss, or feeding refusal). Important causes of these symptoms include (table 5):

Pyloric stenosis — Pyloric stenosis is the most common cause of obstruction in infants. It typically presents with immediate postprandial vomiting in infants <12 weeks of age (usually between three and six weeks) and is more common in males. It is a condition of hypertrophy of the pylorus, with elongation and thickening, eventually progressing to near-complete obstruction of the gastric outlet. (See "Infantile hypertrophic pyloric stenosis".)

The vomiting is nonbilious and forceful or may become more forceful over time, with associated weight loss. A minority of infants develop electrolyte imbalances, particularly hypochloremia, due to loss of gastric hydrochloric acid. An "olive-like" mass is often palpable at the lateral edge of the rectus abdominis muscle in the right upper quadrant of the abdomen. Infants who present very early or those who are premature tend to have more subtle signs and symptoms at presentation. The diagnosis is generally made by abdominal ultrasound, and surgical treatment is curative.

Intestinal obstruction — Bilious (bile-stained) vomitus in a neonate should be treated as a life-threatening emergency because this is often a symptom of obstruction due to intestinal atresia or midgut volvulus [3]. Bilious vomiting occasionally occurs in infants without bowel obstruction. Vomiting that is not bilious may be caused by proximal obstruction, most commonly pyloric stenosis (see 'Pyloric stenosis' above) and, rarely, upper duodenal stenosis, gastric volvulus, or annular pancreas [5].

●Causes – Causes of intestinal obstruction that present during early infancy include [6]:

•Intestinal atresia – Intestinal atresia typically presents with vomiting (usually bilious) beginning in the first two days of life. Many patients fail to pass meconium, depending on the level of obstruction. (See "Intestinal atresia".)

•Intestinal volvulus – Intestinal volvulus presents with sudden onset of vomiting (usually bilious) with an acute abdomen. It is usually associated with underlying malrotation, an anomaly of fetal intestinal development in which the cecum is abnormally positioned in the right upper quadrant and is fixated to the right lateral abdominal wall by bands of peritoneum. These abnormalities predispose to intestinal volvulus, in which the intestine twists on its mesentery, causing acute small bowel obstruction and ischemia. Infants with malrotation also may present with signs of duodenal obstruction (due to Ladd bands that cross the duodenum) or with associated congenital anomalies such as intestinal atresia or stenosis. (See "Intestinal malrotation in children".)

Volvulus occurs early in infancy in approximately one-half of infants with malrotation. Other infants with malrotation may remain asymptomatic or present later in childhood with acute or chronic symptoms. (See 'Malrotation' below.)

•Hirschsprung disease – Most patients with Hirschsprung disease are diagnosed in the neonatal period, presenting with symptoms of distal intestinal obstruction: bilious emesis, abdominal distension, and failure to pass stool. The diagnosis can be suggested by a delay in passage of the first meconium (greater than 48 hours of age). The disorder can also present initially with enterocolitis, a potentially life-threatening illness in which patients have a sepsis-like picture with fever, vomiting, diarrhea, and abdominal distension, which can progress to toxic megacolon. (See "Congenital aganglionic megacolon (Hirschsprung disease)".)

•Intussusception – Occasionally, intussusception presents in young infants, although it is most common between 6 and 36 months of age. (See 'Intussusception' below and "Intussusception in children".)

●Imaging – If intestinal obstruction is suspected, the specific diagnosis often can be suggested by the patient's history and with appropriate radiologic imaging, as outlined in this appropriateness criteria table for infants [7]. In general:

•Conventional abdominal radiograph – Appropriate for suspected bowel obstruction; it provides a rapid assessment of obstruction with relatively little radiation exposure.

•Abdominal ultrasound – The procedure of choice for detecting pyloric stenosis and intussusception.

•Upper gastrointestinal contrast study – Usually appropriate if a diagnosis is not established by ultrasound and proximal bowel obstruction is suspected.

•Contrast enema – Usually appropriate if the abdominal radiograph or physical examination suggests distal bowel obstruction (as might be seen in Hirschsprung disease). A contrast enema may be used for diagnostic and therapeutic purposes for intussusception.

Inborn errors of metabolism — Inborn errors of metabolism are rare causes of vomiting in neonates and young infants. Nonetheless, recognition of these disorders is important because prompt initiation of appropriate therapy can be lifesaving and prevent long-term complications. The clinical presentation varies with the type of metabolic disorder. (See "Inborn errors of metabolism: Epidemiology, pathogenesis, and clinical features" and "Metabolic emergencies in suspected inborn errors of metabolism: Presentation, evaluation, and management".)

●Organic acidemias – The typical presentation of organic acidemias in newborns is an acute, severe illness characterized by lethargy, poor feeding, vomiting, metabolic acidosis, and shock. (See "Organic acidemias: An overview and specific defects".)

●Urea cycle disorders – Urea cycle disorders typically present during infancy or early childhood, with episodes of altered mental status with gastrointestinal symptoms and hyperammonemia, often triggered by catabolic stress (intercurrent illness or fasting) or increased protein load. (See "Urea cycle disorders: Clinical features and diagnosis".)

●Galactosemia – Infants with classic galactosemia usually present in the first few days after birth and initiation of breast milk or cow's milk-based formula feedings. Typical symptoms include jaundice, vomiting, hepatomegaly, failure to thrive, poor feeding, and susceptibility to gram-negative infections; some develop lenticular cataracts. (See "Galactosemia: Clinical features and diagnosis".)

●Hereditary fructose intolerance – Most cases of hereditary fructose intolerance present with recurrent hypoglycemia and vomiting at the age of weaning, when fructose or sucrose (a disaccharide that is hydrolyzed to glucose and fructose) typically is added to the infant diet. However, some infants may present earlier because many commercial formulas and medications contain sucrose or fructose. (See "Causes of hypoglycemia in infants and children", section on 'Hereditary fructose intolerance'.)

Immunologic reactions to food — Immunologic reactions to food that present with vomiting in infancy include:

●Food protein-induced enterocolitis syndrome (FPIES) – FPIES is an uncommon gastrointestinal food hypersensitivity that manifests as profuse, repetitive vomiting, often with diarrhea, leading to dehydration and lethargy in the acute setting (typically within one to three hours of ingestion) or weight loss and failure to thrive in a chronic form. The disease usually begins in early infancy, within one to four weeks following introduction of cow's milk or soy protein. It is most commonly caused by cow's milk or soy protein, although other foods can be triggers; it is uncommon in breastfed infants. FPIES is a non-immunoglobulin E (IgE)-mediated reaction to food, similar to food protein-induced enteropathy but with more severe manifestations. (See "Food protein-induced enterocolitis syndrome (FPIES)".)

The term "food protein-induced enteropathy" has been used to describe an immunologic reaction to dietary proteins that causes a diffuse enteritis and presents with subacute onset of vomiting, diarrhea, and poor weight gain, sometimes with bloody stools. This is an older diagnostic term based on findings of flattened intestinal villi, and the disorder likely overlaps with the more current diagnostic category chronic FPIES, which is based on clinical description only (without biopsy). (See "Food protein-induced enterocolitis syndrome (FPIES)", section on 'Allergic food protein-induced proctocolitis and enteropathy'.)

●IgE-mediated food allergy – IgE-mediated food allergies can present any time after a dietary protein is introduced. They generally occur shortly after ingestion of the allergen (usually within minutes). Vomiting is a very common manifestation, often in conjunction with other symptoms such as diarrhea, urticaria, or wheezing. In young infants, a common trigger is cow's milk protein. This is most common in infants fed a cow's milk-based formula or complementary food (eg, yogurt) but occasionally occurs in exclusively breastfed infants. (See "Milk allergy: Clinical features and diagnosis" and 'Food allergy' below.)

A more common immunologic reaction to food in infants is isolated allergic proctocolitis, which presents with bloody stools, usually without vomiting in an otherwise healthy infant. (See "Food protein-induced allergic proctocolitis of infancy".)

Adrenal insufficiency — Neonates presenting with symptoms similar to those of pyloric stenosis, but with hyponatremia, hyperkalemic acidosis, and/or disproportionate hypotension, should raise concern for adrenal crisis. This is a life-threatening condition and should be evaluated and treated urgently. Adrenal crisis occasionally presents in older individuals with risk factors for adrenal insufficiency. (See 'Adrenal crisis' below.)

The most common cause of adrenal insufficiency in infants is congenital adrenal hyperplasia due to 21-hydroxylase deficiency. In the United States, 21-hydroxylase deficiency is part of the newborn screen in most states, so most (but not all) affected infants will be diagnosed prior to developing adrenal crisis. Adrenal crisis usually presents between the first and fourth week of life. Affected females have atypical genitalia; males usually have no obvious genital abnormalities. (See "Clinical manifestations and diagnosis of adrenal insufficiency in children", section on 'Adrenal crisis'.)

DISORDERS SEEN IN MANY AGE GROUPS — Important causes of vomiting in older infants, children, and adolescents are listed in the table and outlined below (table 6):

Infectious causes

Gastroenteritis — Gastroenteritis is by far the most common cause of vomiting in infants, children, and adolescents and is usually caused by a virus. The vomiting is sudden in onset, quick to resolve, and often associated with diarrhea. Ill contacts or clusters of cases are common. Bacterial causes of gastroenteritis may be associated with more prolonged and severe illness. (See "Acute viral gastroenteritis in children in resource-abundant countries: Clinical features and diagnosis" and "Clinical manifestations and diagnosis of rotavirus infection", section on 'Clinical manifestations'.)

Other infections — Pharyngitis (particularly streptococcal pharyngitis), otitis media, and urinary tract infections are often associated with nausea and/or vomiting, particularly in young children. (See "Group A streptococcal tonsillopharyngitis in children and adolescents: Clinical features and diagnosis", section on 'Clinical features' and "Urinary tract infections in infants and children older than one month: Clinical features and diagnosis", section on 'Clinical presentation'.)

Gastrointestinal obstruction

Intussusception — Intussusception is the most common cause of intestinal obstruction in children between 6 and 36 months of age but occasionally occurs in younger infants or older children. In some cases, especially those presenting outside of the typical age range, there is an associated pathologic lead point, such as a Meckel diverticulum, duplication cyst, or polyp.

Patients with intussusception typically present with sudden onset of intermittent, severe, crampy, progressive abdominal pain, accompanied by inconsolable crying and drawing up of the legs toward the abdomen. The episodes become more frequent and more severe over time. Vomiting may follow episodes of abdominal pain. Initially, emesis is nonbilious, but it may become bilious as the obstruction progresses. A sausage-shaped abdominal mass may be felt in the right side of the abdomen. As symptoms progress, increasing lethargy develops, which can be mistaken for meningoencephalitis. In up to 70 percent of cases, the stool contains gross or occult blood. In infants, intussusception may present as lethargy with or without vomiting or rectal bleeding. (See "Intussusception in children".)

Malrotation — Intestinal malrotation is a congenital anomaly that can present with symptoms at any age or remain asymptomatic. Among those who develop symptoms, approximately one-third present during infancy, typically with acute intestinal obstruction and bilious vomiting due to midgut volvulus [8]. (See 'Intestinal obstruction' above.)

Among those who develop symptoms during childhood or adolescence (approximately 20 percent), the presentation varies from acute obstruction to subacute onset with intermittent abdominal pain, usually but not always with vomiting, which may or may not be bilious.

The clinical presentation, diagnosis, and management of intestinal malrotation are discussed separately. (See "Intestinal malrotation in children".)

Other gastrointestinal causes

Gastroesophageal reflux disease — Gastroesophageal reflux disease (GERD) is an important consideration in infants, children, and adolescents presenting with subacute or chronic nausea or vomiting. The assessment and management of this disorder are discussed in separate topic reviews. (See "Clinical manifestations and diagnosis of gastroesophageal reflux disease in children and adolescents" and "Management of gastroesophageal reflux disease in children and adolescents".)

In infants, most regurgitation is physiologic and inconsequential. A minority of infants who regurgitate have GERD. No specific clinical features definitively identify these infants, but they may have recurrent fussiness or irritability and feeding aversion. These symptoms are thought to result from pain caused by esophageal acid exposure. Reflux may be associated with bradycardia or cyanotic episodes, particularly in preterm or neurologically impaired infants. Poor weight gain despite an adequate intake of calories should prompt evaluation for causes of vomiting and weight loss other than GERD. (See "Gastroesophageal reflux in infants", section on 'Evaluation and management by presenting symptoms'.)

Gastroparesis — Postinfectious gastroparesis is a relatively common cause of vomiting in children. It is a consequence of an acute viral illness (often rotavirus gastroenteritis) that results in chronic postprandial antral hypomotility. Typical symptoms are postprandial fullness and nausea as well as postprandial vomiting. The vomiting usually occurs many hours after ingestion of food, a characteristic that differentiates this entity from GER or rumination syndrome, in which the emesis occurs during or immediately after eating. In most cases, the symptoms resolve spontaneously within 6 to 24 months [9]. (See "Gastroparesis: Etiology, clinical manifestations, and diagnosis".)

Uncommon causes of gastroparesis in children are:

●Surgery with vagus nerve damage (eg, fundoplication)

●Use of drugs such as opioids or anticholinergics

●Metabolic disturbances such as hypokalemia, acidosis, or hypothyroidism

●Eosinophilic gastroenteropathy

●Neuromuscular disorders such as cerebral palsy, diabetes mellitus, pseudo-obstruction, and muscular dystrophy

Appendicitis — Appendicitis presents most frequently in the second decade of life and is the most common indication for emergency abdominal surgery in childhood.

Typical symptoms are:

●Early symptoms – Often subtle and nonspecific, including indigestion, flatulence, bowel irregularity, and malaise.

●Pain – Subsequently, pain develops in the epigastrium or periumbilical region, which is visceral in character (ie, constant, not very severe in intensity, and poorly localizable). The location of the pain may vary depending on the location of the appendix. An inflamed anterior or pelvic appendix produces marked symptoms in the right lower quadrant, while a retrocecal appendix may not cause the same degree of local signs of peritonitis, because the inflammation is masked by the overlying bowel. The pain eventually localizes to the right lower quadrant once inflammation involves the overlying parietal peritoneum.

●Nausea and vomiting – If nausea and vomiting occur, they follow the onset of pain. The diagnosis of appendicitis is less likely in patients in whom nausea and emesis are the first signs of illness. (See "Acute appendicitis in children: Clinical manifestations and diagnosis".)

Eosinophilic esophagitis or gastroenteritis — Eosinophilic disease can affect multiple parts of the upper gastrointestinal tract, together or separately.

●Eosinophilic esophagitis is much more common in males than in females. Toddlers tend to experience epigastric pain, nausea and vomiting, and feeding aversion. Adolescents tend to have symptoms of dysphagia and may present with an acute food impaction [10]. In many cases, the disorder appears to be mediated by a delayed, cell-mediated hypersensitivity to foods. Many but not all patients have associated allergic disorders such as eczema and asthma. (See "Clinical manifestations and diagnosis of eosinophilic esophagitis (EoE)".)

●Eosinophilic gastroenteritis can present at any age with abdominal pain, nausea, diarrhea, malabsorption, hypoalbuminemia, and weight loss. Symptoms vary depending on the layer and site of involved gastrointestinal tract. In adolescents and adults, it can also present with nausea and vomiting or may mimic irritable bowel syndrome. In infants, it may present as gastric outlet obstruction with postprandial projectile vomiting, mimicking pyloric stenosis. Approximately one-half of patients have allergic disease, such as defined food allergies, asthma, eczema, or rhinitis. (See "Eosinophilic gastrointestinal diseases".)

Inflammatory bowel disease — inflammatory bowel disease (IBD; ulcerative colitis and Crohn disease) may present with complaints of nausea, but frank vomiting is rarely a primary presenting symptom. These diseases should be considered if there are suggestive chronic features in the history and clinical presentation, especially growth failure, diarrhea (with or without blood), abdominal pain, perianal disease, anemia, or arthritis. (See "Clinical presentation and diagnosis of inflammatory bowel disease in children".)

Functional gastrointestinal disorders

Functional dyspepsia — Dyspepsia is defined by a persistent or recurrent pain or discomfort localized to the upper abdomen; it is often associated with postprandial nausea, vomiting, and early satiety. In most cases, dyspepsia appears to be functional in nature due to a disorder of upper gastrointestinal sensation and motility [11]. Patients with functional dyspepsia often report nausea or postprandial distress, but persistent vomiting is uncommon.

Functional dyspepsia must be distinguished from dyspepsia caused by an organic disease such as peptic ulcer (with or without underlying Helicobacter pylori infection), food allergy, or Crohn disease. The approach to the adolescent patient with dyspeptic symptoms and a more detailed discussion of functional dyspepsia are given separately. (See "Chronic abdominal pain in children and adolescents: Approach to the evaluation", section on 'Functional disorders' and "Approach to the adult with dyspepsia".)

Functional nausea and functional vomiting — These categories were added to the descriptions of functional gastrointestinal disorders in the 2016 Rome IV classification [12]. By definition, these disorders are not otherwise explained and the vomiting is not self-induced; they are distinguished from functional dyspepsia by the absence of abdominal pain. They occur in approximately 1 percent of school-aged children and adolescents [13,14].

Some patients have nausea alone, others have vomiting alone, and others have both symptoms; there may be associated autonomic symptoms such as pallor, sweating, or dizziness. They are more common in individuals with underlying anxiety or depression. Patients often report early morning nausea that improves throughout the day [15].

The diagnosis requires excluding other causes of the symptoms, usually with a focused history and physical examination, considering especially pregnancy, postviral gastroparesis (see 'Gastroparesis' above), and intracranial hypertension (suggested by weight loss, neurologic symptoms, severe morning vomiting or headaches) (see 'Intracranial hypertension' below). Endoscopy is sometimes appropriate but not required to make the diagnosis [12]. In addition, the diagnosis is supported by the presence of risk factors for functional gastrointestinal disorders, including psychological distress or a family history of functional gastrointestinal disorders.

Similar to other functional gastrointestinal disorders, the most valuable intervention for functional nausea and vomiting is an interdisciplinary approach addressing the psychosocial contributors, which may include reassurance, relaxation strategies, and/or cognitive behavioral therapy. Antiemetic medications are generally ineffective for functional nausea. Selected patients with refractory functional nausea after referral to a specialist may benefit from a trial of pharmacotherapy with cyproheptadine or antidepressants [15-17]. (See "Functional abdominal pain in children and adolescents: Management in primary care".)

Cyclic vomiting syndrome — Cyclic vomiting syndrome is a disorder characterized by repeated episodes of nausea and vomiting that last for hours to days separated by symptom-free periods of variable length. This pattern of episodic emesis is quite distinct from most other causes of vomiting. Intense vomiting and nausea are the cardinal symptoms and usually lead to significant deficits of fluids and electrolytes. A notable feature is compulsive hot water bathing during an episode; this behavior is also seen in cannabis hyperemesis syndrome.

Cyclic vomiting has been most often described in school-aged children but may affect other age groups. The etiology is unknown, but many patients have a personal or family history of migraine headaches, suggesting that there may be a common pathophysiologic process. (See "Cyclic vomiting syndrome".)

Cannabis hyperemesis syndrome — Chronic use of cannabis in adolescents may trigger episodes of vomiting that resemble cyclic vomiting syndrome. Diagnostic criteria include [18]:

●Onset after prolonged, excessive cannabis use

●Relief of vomiting episodes by sustained cessation of cannabis use

The syndrome is also associated with pathologic bathing behavior (prolonged hot baths or showers), which supports the diagnosis. However, these behaviors are also found in cyclic vomiting syndrome. (See "Cannabis use and disorder: Epidemiology, pharmacology, comorbidities, and adverse effects", section on 'Medical and systemic effects'.)

Rumination syndrome — Rumination syndrome is characterized by effortless regurgitation and rechewing or expulsion of food beginning soon after a meal, without nausea or retching [12]. The symptoms disappear hours after eating, once the regurgitated material becomes acidic, and do not occur during sleep. (See "Rumination syndrome".)

Rumination syndrome has been described in infants with sensory and emotional deprivation [19]. The disorder occurs more commonly in older children and is especially prevalent in adolescent girls [12,20]. The severity of adolescent rumination syndrome varies, ranging from a benign disorder amenable to behavioral therapies to much more severe forms associated with substantial weight loss and inability to attend school [21]. (See "Eating disorders: Overview of epidemiology, clinical features, and diagnosis", section on 'Rumination disorder' and "Management of gastroesophageal reflux disease in children and adolescents", section on 'Rumination'.)

Endocrine/metabolic

Diabetic ketoacidosis — Approximately 30 percent of children with type 1 diabetes first present with signs and symptoms of diabetic ketoacidosis. Most present with anorexia, nausea, vomiting, abdominal pain, and polyuria, sometimes with neurologic symptoms. The onset can be insidious so that the diagnosis is not recognized until laboratory testing is performed. The symptoms may be harder to appreciate in infants and very young children who are not toilet trained, leading to delayed diagnosis and more severe ketoacidosis. (See "Diabetic ketoacidosis in children: Clinical features and diagnosis".)

Adrenal crisis — Adrenal crisis is uncommon but should be considered as a cause of unexplained vomiting in children of any age with:

●Risk factors for adrenal insufficiency – Known adrenal insufficiency, history of glucocorticoid use

●Suspicious symptoms and signs – Disproportionate hypotension, hyponatremia, and/or hyperkalemic acidosis and hyperpigmentation

Adrenal crisis is a medical emergency requiring immediate treatment with intravenous fluids and stress doses of glucocorticoids. Clinical features and management of adrenal crisis are summarized in the table (table 7) and discussed in more detail in a separate topic review.(See "Clinical manifestations and diagnosis of adrenal insufficiency in children", section on 'Adrenal crisis'.)

Neurologic

Intracranial hypertension — Brain tumors and other intracranial masses can cause vomiting by increasing the intracranial pressure (ICP) at the area postrema of the medulla. (See "Elevated intracranial pressure (ICP) in children: Clinical manifestations and diagnosis".)

Clinical characteristics suggesting increased ICP include emesis that is triggered by an abrupt change in body position, especially upon awakening, with little or no accompanying nausea. More importantly, neurogenic vomiting usually is associated with other neurologic symptoms such as headache or focal neurologic deficit, although these signs and symptoms may be subtle. (See "Overview of the clinical features and diagnosis of brain tumors in adults".)

Idiopathic intracranial hypertension (pseudotumor cerebri) refers to increased ICP with normal cerebrospinal fluid content, normal neuroimaging, absence of neurologic signs except cranial nerve VI palsy, and no known cause. It is usually associated with headache and, occasionally, with nausea and vomiting. In the pediatric age range, it is most likely to affect adolescent girls who have obesity. (See "Idiopathic intracranial hypertension (pseudotumor cerebri): Clinical features and diagnosis".)

Migraine — Migraine is characterized by periodic episodes of paroxysmal headache, often accompanied by nausea, vomiting, and abdominal pain and often with vertigo, relieved by sleep. The disorder occurs at all ages, beginning before age 20 years in 50 percent of cases. The family history is positive in most patients. Migraine usually can be distinguished from other causes of vomiting by the periodic nature and associated characteristic headache with photophobia and phonophobia. (See "Pathophysiology, clinical features, and diagnosis of migraine in children".)

Miscellaneous

Posttussive — Posttussive emesis is a common consequence of vigorous or paroxysmal coughing. It is a classic symptom of pertussis infection but also can occur with vigorous coughing from any cause, including asthma or an airway foreign body [22,23]. It may also occur in children with developmental disabilities who may have abnormal swallowing and may choke and cough when oral and nasal secretions accumulate in the hypopharynx. The cough is then often followed by vomiting. (See "Pertussis infection in infants and children: Clinical features and diagnosis" and "Airway foreign bodies in children" and "Approach to chronic cough in children".)

Food allergy — Anaphylaxis is an IgE-mediated hypersensitivity reaction. When triggered by ingested substances (typically foods or medications), it tends to present with prominent gastrointestinal symptoms, including nausea, crampy or colicky abdominal pain, vomiting (sometimes large quantities of "stringy" mucus), and diarrhea. The symptoms' reactions are rapid in onset, typically beginning within minutes to two hours from the time of ingestion.

Gastrointestinal symptoms are rarely the sole manifestations of a food-allergic reaction. Concurrent anaphylactic symptoms may include pruritus, flushing, urticaria/angioedema, periorbital edema, conjunctival injection, rhinorrhea, nasal congestion, cough, wheezing, dyspnea, change of voice quality, sense of choking, tachycardia (or, less commonly, bradycardia), dizziness, hypotension, sense of impending doom, and cardiovascular collapse.

In most cases, an allergic reaction to food can be readily distinguished from other causes of vomiting by the presence of concurrent anaphylactic symptoms and by the history. The diagnosis and treatment of anaphylaxis are reviewed separately. (See "Anaphylaxis: Emergency treatment" and "Clinical manifestations of food allergy: An overview" and "Food allergy in children: Prevalence, natural history, and monitoring for resolution".)

Pregnancy — Pediatricians should have a low threshold for suspecting pregnancy in adolescents. Adolescents may present with complaints of menstrual irregularity, abdominal pain, or other symptoms. These complaints may represent a "hidden agenda," or the adolescent may not have considered the possibility of pregnancy. (See "Pregnancy in adolescents", section on 'Diagnosis of pregnancy'.)

Bulimia — Bulimia nervosa is characterized by episodes of binge eating, with inappropriate compensatory behavior to prevent weight gain (typically vomiting). The vomiting is typically self-induced, but some patients can trigger vomiting at will. This diagnosis should be considered in a patient with excessive concerns about body weight and shape. Most but not all cases are in females, with onset during adolescence or young adulthood. (See "Eating disorders: Overview of epidemiology, clinical features, and diagnosis", section on 'Bulimia nervosa'.)

Toxic ingestions — Toxic ingestions often present with vomiting and/or altered mental status, especially in a younger child with acute onset of symptoms. Particular considerations for a young child include lead toxicity and any medications or household cleaning agents that the child may have had access to. Common ingestions in adolescents are alcohol and recreational drugs. (See "Approach to the child with occult toxic exposure".)

Medical child abuse — Medical child abuse consists of a caregiver fabricating or inducing illness in a child in order to get attention. The patient may have a history of frequent recurrent illnesses without a clear etiology. As an example, ipecac poisoning can present with recurrent, unexplained vomiting and repeated hospitalizations; the diagnosis can be confirmed by urine toxicology [24,25]. (See "Medical child abuse (Munchausen syndrome by proxy)".)

The diagnosis should be considered if the following features are present:

●Reported history varies from what is observed or does not make sense

●Illness is unexplained, unusual, or prolonged and does not respond to treatment as expected

●Symptoms seem to originate only in the presence of the suspected perpetrator

●Problem resolves or improves when the child is separated from the suspected perpetrator

●Problem recurs when the suspected perpetrator is told that the child is improving or is soon to be released from the hospital or treatment program

●Family members (eg, siblings) have unexplained symptoms, illness, or death

●Suspected perpetrator behaves in a manner that appears to be consistent with exaggeration, fabrication, or induction of physical, psychological, or behavioral problems in the child

●Alleged perpetrator does not seem to be as worried by the child's illness as the health professionals who are caring for the child

Diagnostic differences between children and adolescents — There are a few notable differences in the diagnostic profile between children and adolescents:

●Pregnancy and acute intermittent porphyria can present with vomiting in postpubertal adolescents. Migraines, bulimia, and cannabis hyperemesis syndrome also occur more frequently in adolescents than in children.

●In contrast, intussusception, renal hydronephrosis, and medical child abuse occur more commonly during childhood.

TREATMENT — Treatment of nausea and vomiting depends on the underlying etiology:

●Targeted treatment – Provide targeted therapy if appropriate for the cause, such as nonoperative reduction for intussusception, surgery for bowel obstruction or appendicitis, or insulin for diabetic ketoacidosis.

●Supportive care – Correct any electrolyte abnormalities, metabolic abnormalities, or nutritional deficiencies. Offer referral for cognitive-behavioral interventions for vomiting associated with functional dyspepsia, adolescent rumination syndrome, and bulimia.

●Antiemetics – Antiemetics are useful for selected causes of persistent vomiting to avoid electrolyte abnormalities or nutritional sequelae. They are not generally recommended for vomiting of unknown etiology and are not appropriate for treatment of vomiting caused by anatomic abnormalities or surgical abdomen; they are also contraindicated in infants.

Selection of antiemetics varies with the cause of the vomiting, as summarized in the table (table 8); more details are available in the linked topic reviews:

•Gastroenteritis. (See "Oral rehydration therapy", section on 'Antiemetic therapy' and "Acute viral gastroenteritis in children in resource-abundant countries: Management and prevention", section on 'Antiemetic agents'.)

•Cyclic vomiting syndrome. (See "Cyclic vomiting syndrome", section on 'Management'.)

•Motion sickness – The first-line approach for preventing motion sickness is to avoid environmental triggers, such as reading or viewing a screen while riding in a car. Drug therapy for motion sickness depends on inhibition of activity in the vestibular nuclei, where labyrinthine and visual sensory cues are combined and synthesized. Drugs that reduce activity in the vestibular nuclei include antihistamines and anticholinergics [2]. (See "Motion sickness".)

•Gastroparesis – The prokinetic agents erythromycin, metoclopramide, and domperidone have a role in the management of chronic intestinal pseudo-obstruction and gastroparesis (including postinfectious gastroparesis) [9]. The US Food and Drug Administration has issued a "boxed warning" about the potential for tardive dyskinesia associated with chronic or high-dose use of metoclopramide. Hence, this drug should be used only after a careful discussion with the patient and his or her caretakers about its possible risks and benefits. Drug selection and the potential adverse effects of these drugs are discussed separately. (See "Treatment of gastroparesis", section on 'Prokinetics' and "Chronic intestinal pseudo-obstruction: Management", section on 'Initial management'.)

•Postoperative nausea and vomiting – During the last two decades, there have been considerable advances in the development of antiemetics. These include the emergence of 5-hydroxytryptamine 3 receptor (5-HT₃) antagonists (ondansetron, granisetron), which have one primary site of antagonism and have helped in the treatment of postoperative nausea and vomiting as well as chemotherapy-associated emesis [2,26]. (See "Postoperative nausea and vomiting".)

•Chemotherapy-induced nausea and vomiting – Tremendous strides have been made in development of antiemetics over the past two decades, especially 5-HT₃ antagonists (ondansetron) and neurokinin 1 (NK1) antagonists (aprepitant). Factors that increase the incidence of vomiting include young age (toddler), female sex, agent emetogenicity (especially cisplatin), and higher rate of administration. 5-HT₃ antagonists are generally effective in the acute phase (the first 24 hours), whereas NK1 antagonists are more effective in the delayed phase >24 hours.

●Complementary and alternative medicine – Patients and families/caregivers are increasingly turning to complementary and alternative medicine for a variety of complaints, particularly if the symptom is chronic or does not have a clear diagnostic explanation [27]. Applications of these techniques to the symptoms of nausea and vomiting have not been well studied, but there is some evidence for efficacy of some nutraceuticals, such as ginger and other herbal compounds for functional dyspepsia and other motility disorders [11,28,29]. Hypnotherapy is often helpful for treatment of anticipatory nausea and vomiting (eg, prior to chemotherapy) [30] and has been found beneficial in children with functional nausea [31]. The definitions and general approaches of other complementary and alternative techniques are discussed separately. (See "Complementary and integrative health in pediatrics".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Nausea and vomiting".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Pyloric stenosis in babies (The Basics)")

●Beyond the Basics topic (see "Patient education: Nausea and vomiting in infants and children (Beyond the Basics)")

SUMMARY

●Goals – Nausea and vomiting may be caused by a wide range of conditions affecting several different organ systems, with vastly different health implications. The goals of the evaluation are to quickly identify serious conditions for which immediate intervention is required and then to identify a specific cause of the symptoms to guide management. (See 'Clinical approach' above.)

●Causes – The causes of vomiting vary by age at presentation:

•Disorders primarily seen in neonates and young infants (table 5) (see 'Disorders primarily seen in neonates and young infants' above)

•Disorders in older infants, children, and adolescents (table 6) (see 'Disorders seen in many age groups' above)

●Evaluation – In many cases, the cause of the nausea and vomiting can be determined from the history and physical examination. The differential diagnosis is informed by the child's age and whether the nausea and vomiting are acute, chronic, or episodic. The diagnostic evaluation includes:

•A focused history and physical examination (table 3) (see 'History' above and 'Physical examination' above)

•Laboratory testing, guided by the history and physical examination (table 4) (see 'Laboratory testing' above)

●Concerning signs – The following symptoms and signs provide important clues to disorders requiring urgent intervention (table 2) (see 'Concerning signs' above and 'History' above and 'Physical examination' above):

•Prolonged vomiting – Prolonged vomiting (eg, >12 hours in a neonate, >24 hours in children younger than two years, and >48 hours in older children) suggests a cause that may require urgent intervention. In addition, patients with prolonged vomiting are at risk for developing dehydration and electrolyte abnormalities.

•Obstruction – Symptoms and signs suggestive of intestinal obstruction include marked abdominal distension, visible bowel loops, absent bowel sounds or increased high-pitched bowel sounds ("borborygmi"), severe abdominal pain, or vomitus that is bilious (green or yellow) or feculent (with the odor of feces).

-In a neonate, bilious vomiting is a particularly important warning sign of possible intestinal obstruction in a neonate (eg, due to intestinal atresia or volvulus). (See 'Intestinal obstruction' above.)

-In an infant or toddler, the sudden onset of intermittent, severe, crampy, progressive abdominal pain suggests the possibility of intussusception, which is the most common cause of intestinal obstruction in infants between 6 and 36 months of age. (See 'Intussusception' above.)

•Neurologic symptoms – Headache, positional triggers for vomiting, vomiting upon awakening, and/or lack of nausea suggest the possibility of increased intracranial pressure (ICP). An adolescent female with early morning vomiting also should be evaluated for pregnancy. (See 'Intracranial hypertension' above.)

Altered consciousness, seizures, or focal neurologic abnormalities suggest the possibility of toxic ingestion or central nervous system mass (all ages), inborn error of metabolism (primarily infants and toddlers), or diabetic ketoacidosis (primarily children and adolescents). (See 'Intracranial hypertension' above and 'Inborn errors of metabolism' above.)

•Hypotension – Hypotension disproportionate to the apparent illness and/or hyperkalemia suggest the possibility of adrenal crisis. (See 'Adrenal crisis' above.)

•Recurrent episodes – Recurrent episodes of vomiting and dehydration in an infant or young child suggest the possibility of an inborn error of metabolism, particularly organic acidemias and urea cycle disorders. Similar patterns are seen in cyclic vomiting syndrome, which is most common in school-aged children. Migraine also may present with sporadic or periodic vomiting but can usually be distinguished by the family history of migraine and associated headache. (See 'Inborn errors of metabolism' above and 'Cyclic vomiting syndrome' above and 'Migraine' above.)

●Treatment – Treatment of nausea and vomiting depends on the underlying etiology and involves targeted treatment for certain disorders, supportive care, and, occasionally, antiemetics (table 8) (for selected patients). (See 'Treatment' above.)