Differentials
Food poisoning
SIGNS / SYMPTOMS
Typically history of acute diarrhea (<2 weeks), recent history of travel, eating contaminated food, or contact with cases of food poisoning (family or friends with similar symptoms).
May have a history of bloody stools.
INVESTIGATIONS
Positive stool cultures and blood cultures for enteric or invasive bacterial infection, or positive stool microscopy for specific ova and/or parasites.
Foodborne E coli infection
SIGNS / SYMPTOMS
Typically history of acute diarrhea (<2 weeks), recent history of travel, eating contaminated food, or contact with an infected person.
May have a history of bloody diarrhea.
INVESTIGATIONS
Positive stool culture for pathogenic Escherichia coli species such as E coli O157:H7.
Crohn disease
SIGNS / SYMPTOMS
Abdominal cramp or constant abdominal pain that may be partially relieved by defecation.
Perianal lesions may be present.
Family history of Crohn disease.
INVESTIGATIONS
Ileocolonoscopy may show any or all of patchy mucosal nodularity, edema, ulcerations, friability, and stenosis.[53]
Mucosal bowel biopsies may demonstrate transmural involvement with noncaseating granulomas.
Ulcerative colitis
SIGNS / SYMPTOMS
Diarrhea is typically bloody, usually with associated tenesmus and abdominal pain.
Family history of ulcerative colitis.
INVESTIGATIONS
Ileocolonoscopy may show any or all of rectal involvement, continuous uniform involvement, loss of vascular marking, diffuse erythema, mucosal granularity, normal terminal ileum (or mild "backwash" ileitis in pancolitis).[54]
Celiac disease
SIGNS / SYMPTOMS
Pronounced weight loss, fatigue, lethargy, nausea, and vomiting may be present.
A skin rash consistent with dermatitis herpetiformis may be present.
INVESTIGATIONS
Elevated immunoglobulin A-tissue transglutaminase titer; however, a normal level does not exclude celiac disease as seronegative celiac disease occurs in a minority of patients.[51]
Increased intraepithelial lymphocytes, villous atrophy, and crypt hyperplasia on duodenal biopsy.
Irritable bowel syndrome
SIGNS / SYMPTOMS
Bloating, flatulence, and crampy abdominal pain relieved by defecation may be present; diarrhea may coexist with periods of constipation.
Family history of irritable bowel syndrome.
INVESTIGATIONS
Normal colonoscopy and pathology from colonic biopsies. Diagnosis is clinical based on positive symptom criteria.[57]
Giardiasis
SIGNS / SYMPTOMS
A history of contact with contaminated water.
Bloating with cramps, frequent belching with a sulfur smell, nausea, anorexia.
INVESTIGATIONS
A stool microscopy for ova and parasites shows presence of cysts and trophozoites.[5]
Lactase deficiency
SIGNS / SYMPTOMS
Usually explosive, bulky and frothy watery stool after ingestion of lactose-containing products.
INVESTIGATIONS
A trial of dietary lactose elimination results in resolution of symptoms once lactose-containing dairy and nondairy products are eliminated from diet. Symptoms resume when these are reintroduced.
Use of this content is subject to our disclaimer