Microscopic colitis typically presents in people >50 years with chronic, nonbloody, watery diarrhea and is more common in women than in men. Other common symptoms include fecal urgency, fecal incontinence, and nocturnal stools. Symptoms can lead to a significantly impaired quality of life.
Most investigations are carried out to rule out other causes of chronic diarrhea such as inflammatory bowel disease, celiac disease, and irritable bowel syndrome.
Diagnosis of microscopic colitis is confirmed by the presence of characteristic pathohistologic findings from ileocolonoscopy biopsies taken from the right and left colon. The colonic mucosa has a normal or near-normal gross appearance on ileocolonoscopy.
Treatment aims to achieve clinical remission (<3 stools per day and <1 watery stool per day) and improve quality of life. Drug choice depends on the severity and extent of disease and includes antidiarrheals, bismuth subsalicylate, oral budesonide, bile acid sequestrants, and immunosuppressants or biologic agents. All patients should additionally have modification of contributing factors, including diet changes if appropriate, avoiding/withdrawing culprit medications, and encouraging cigarette smokers to cease.
Despite high rates of response to medical treatment, the relapse rate after discontinuation is 60% to 80% of patients with variable time to relapse. In patients with recurrent disease, consider re-treatment with prior therapies or with biologics for patients with severe refractory symptoms.
Microscopic colitis is an inflammatory disease of the colon characterized by chronic watery, nonbloody diarrhea and a normal or near-normal appearance on colonoscopy. It mostly affects older adults (>50 years) and is rare in children. Diagnosis is based on abnormal histological features from biopsies from the left and right colon. Microscopic colitis encompassess two major different subtypes based on histology: lymphocytic colitis and collagenous colitis. Both subtypes typically have similar clinical features. There is a subset of patients who do not meet histologic criteria; these patients may be diagnosed as "microscopic colitis not otherwise specified" or "microscopic colitis incomplete."
This topic covers microscopic colitis in adults.
History and exam
Key diagnostic factors
- presence of risk factors
- chronic watery, nonbloody diarrhea
Other diagnostic factors
- fecal urgency
- fecal incontinence
- nocturnal stools
- abdominal pain
- weight loss
- age >50 years
- cigarette smoking
- female sex
- autoimmune disorders
- use of certain medications
1st investigations to order
- basic metabolic panel
- erythrocyte sedimentation rate
- immunoglobulin A-tissue transglutaminase
- stool studies for infective pathogens
- stool O+P
- lateral flow immunoassay (Giardia)
- colonic biopsies
Investigations to consider
- flexible sigmoidoscopy with biopsies
mild to moderate disease
relapse after induction of remission
- Food poisoning
- Foodborne E coli infection
- Crohn disease
- European guidelines on microscopic colitis: statements and recommendations
- Guidelines for the investigation of chronic diarrhoea in adults
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