[Microscopic colitis: clinical presentation, treatment and outcome of 494 patients]

Collagenous colitis (CC) and lymphocytic colitis (LC) are chronic disorders characterized by watery diarrhea.

To evaluate prospectively the clinical features, response to treatment and outcomes in a large group of patients with CC and LC.

Patients with histologically confirmed CC and LC were prospectively enrolled to complete a questionnaire on onset and duration of diarrhea, stool frequency and consistency, other gastrointestinal symptoms including weight loss, drug history, treatment success and concomitant diseases.

A total of 494 patients (CC, n = 287, LC, n = 207) were available for analysis. The mean age at diagnosis was 65 in CC and 61 years in LC with a identically female predominance (76 % of patients) in both groups. Prior to diagnosis the mean duration of symptoms was 37 in CC and 23 months in LC. CC and LC patients share similar pattern of clinical symptoms. Concomitant autoimmune disorders were more common in CC patients (48.4 %) than in LC patients (29.6 %). Sustained clinical remission was reported by 35.5 % of CC and 38,6 % of LC, but more CC patients (47.7 %) received medication such as corticosteroids, antibiotics, bismuth or 5-aminosalicyclic than LC patients (16.9 %). 18.6 % of CC patients and 17.6 % of LC were regularly using NSAIDs.

Collagenous and lymphocytic colitis are frequently diagnosed in elderly female patients. CC and LC share similar symptom pattern, but concomitant autoimmune disease were more common in CC than in LC patients.