| | Clinical features | Typical location |
| Common causes |
| Acid peptic disorders (eg, reflux esophagitis, gastritis, gastric and duodenal ulcers, Helicobacter pylori infection) | - Early morning pain, pain awakens at night
- Early satiety, nausea, sour breath, burping
- Occult blood in stool
| Epigastric, upper abdomen |
| Carbohydrate malabsorption (eg, lactose) | - Crampy pain, diarrhea (bulky, watery, frothy), bloating, and/or intestinal gas related to ingestion of foods containing the malabsorbed carbohydrate (eg, dairy products and foods containing dairy products for lactose malabsorption)
| Periumbilical, lower abdomen |
| Celiac disease | - Crampy, nonspecific abdominal pain, chronic diarrhea, anorexia, abdominal distension, poor weight gain or weight loss, malnutrition, steatorrhea, flatulence
- Iron deficiency anemia
- Secondary amenorrhea
| Less likely to be epigastric |
| Constipation (may have organic or functional etiology) | - Infrequent stooling, incomplete evacuation, fecal incontinence, history of large stools or stools that clog the toilet, abdominal distention, mass in the left lower abdominal quadrant, hard stool in rectal vault on digital examination
| Left-sided |
| Dysmenorrhea* | - Cyclical pain related to menstruation
| Lower abdomen |
| Gastroesophageal reflux | - Respiratory symptoms, such a chronic cough, wheezing, laryngitis
| Epigastric, upper abdomen |
| Musculoskeletal pain (eg, hernia, hematoma, anterior cutaneous nerve entrapment syndrome) | - Pain with specific physical activity
- Muscle tenderness on examination
- Positive Carnett sign¶
| Abdominal wall |
| Parasitic infection (eg, Giardia, cryptosporidium) | - Diarrhea, crampy pain, bloating
- Exposure history
| Diffuse |
| Less common causes |
| Endometriosis* | - Severe progressive dysmenorrhea
- May also have bowel symptoms (eg, rectal pain, constipation, painful defecation) and bladder symptoms (eg, dysuria, urgency, hematuria)
| Lower abdomen, pelvis |
| Eosinophilic esophagitis | - Feeding dysfunction, vomiting, dysphagia, food impaction, association with allergic conditions (eg, food allergy, environmental allergy, asthma, atopic dermatitis)
| Upper abdomen or chest |
| Food allergy | - IgE-mediated:
- Onset of abdominal pain, nausea, or vomiting within minutes to 2 hours after ingestion of offending food
- Onset of diarrhea within 2 to 6 hours after ingestion of offending food
- Non-IgE-mediated:
- Chronic vomiting and diarrhea
- Poor weight gain
- Blood or mucus in stools
| Nonspecific |
| Inflammatory bowel disease | - Short stature
- Poor weight gain
- Delayed sexual maturation
- Oral ulcers
- Perianal fistulae, skin tags, and fissures
- Diarrhea
- Gross or occult blood in stool
- Uveitis, arthritis
- Elevated ESR or CRP
| Lower abdomen |
| Pelvic inflammatory disease* | - Cervical motion tenderness, adnexal tenderness, or adnexal mass on pelvic examination
- Pain may have onset or worsen during or shortly after menses
- Abnormal uterine bleeding
- May have RUQ pain with perihepatitis
| Lower abdomen pelvis |
| Urinary tract infection | - Fever, urinary symptoms (dysuria, urgency, frequency, incontinence, macroscopic hematuria), flank pain
| Lower abdomen, flank |
| Rare causes |
| Bezoar | - Nausea, vomiting, early satiety, anorexia, weight loss
- Patchy alopecia in patients with trichobezoars
- History of gastric surgery
| Epigastric |
| Burkitt lymphoma | - Ascites, bowel obstruction, gastrointestinal bleeding
| Diffuse, RLQ |
| Chronic hepatitis | | RUQ |
| Chronic pancreatitis | - Malabsorption, obstructive jaundice, growth failure, epigastric or upper abdominal tenderness that radiates to the back, pain worse after eating (especially fatty food), nausea, vomiting
| Epigastric, upper abdomen |
| Familial Mediterranean fever | - Recurrent unexplained fever
| Diffuse |
| Foreign body | - Clinical features vary with location of foreign body
| Variable |
| Gallstones/chronic cholecystitis/choledochal cyst | - Jaundice, abnormal liver tests (elevation of AST and ALT early in the course; elevation of bilirubin, alkaline phosphatase, and GGT later in the course)
| RUQ or epigastric |
| Heavy metal poisoning (eg, lead) | - Exposure history
- Crampy pain
- Sporadic vomiting
- Constipation
| Diffuse |
| Hereditary angioedema | - Gastrointestinal colic, nausea, vomiting, diarrhea
- Skin symptoms
- Prodromal symptoms
- Attacks may be triggered by mild trauma, medications, hormonal changes
- Recurrent angioedema without urticaria
- Low C4 levels
- Family history of allergy
| Nonspecific |
| Imperforate hymen with hematocolpos* | - Absence of menarche despite sexual maturity
- Cyclic abdominal or pelvic pain
- Imperforate hymen with bluish discoloration
- May have back pain, pain with defecation, or difficulties with urination
| Lower abdomen/pelvis |
| Malrotation (late presentation) | - Episodic episodes of vomiting (not necessarily bilious) and abdominal pain
| Diffuse |
| Mesenteric ischemia | - Postprandial abdominal pain, weight loss, nausea, vomiting, diarrhea
| Diffuse |
| Nephrolithiasis | - Lower abdominal pain may radiate to the genitalia, may have gross hematuria, dysuria, urgency, nausea/vomiting
| Lower abdomen |
| Plasminogen deficiency | - Pseudomembrane formation, can affect any mucosal tissue (conjunctivitis is most common)
- Abdominal pain or other symptoms consistent with inflammatory bowel disease
- Poor wound healing
- Autosomal recessive; siblings may also manifest symptoms
| Diffuse |
| Pregnancy* | - Amenorrhea, nausea, breast enlargement, urinary frequency fatigue
| Lower abdomen |
| Psoas abscess | - Back or flank pain
- Radiation to hip or posterior thigh
- Positive psoas signΔ
| Lower abdomen |
| Slipping rib syndrome[6] | - Sharp unilateral pain, worse with twisting, turning or extension of the thorax
- Pain reproduced by displacing the lower ribs upward and anteriorly with the patient in the supine position
| Upper abdomen |
| Superior mesenteric artery syndrome | - Progressive symptoms of postprandial epigastric pain and early satiety
- Nausea, weight loss
- Abdominal distension
- High pitched bowel sounds
- Symptoms may be relieved in certain positions (eg, prone, left lateral decubitus, knee-chest)
| Epigastric |
| Ureteropelvic junction obstruction | - Intermittent flank or abdominal pain
- Pain may worsen during brisk diuresis (eg, after consumption of caffeine or alcohol), nausea, vomiting
| Periumbilical |
| Vasculitis (eg, Henoch-Schönlein purpura, polyarteritis nodosa) | - Extragastrointestinal manifestations (eg, arthritis, purpura, hematuria)
| Diffuse |
