[Collagenous colitis: clinicopathologic study of 6 new cases]

Collagenous colitis (CC) is a newly recognized entity characterized clinically by chronic watery diarrhoea and pathologically by epithelial inflammatory injury and the presence of a thickened collagen band beneath the surface epithelium of the colon. Clinical and pathological data of six patients (5 women and 1 man, mean age 54 years) with this diagnosis have been reviewed. Chronic watery diarrhoea was the main symptom in all cases, ranging from 2 to 12 bowel movements a day (mean +/- SD, 5.5 +/- 2.3) lasting from 8 months to 19 years (mean +/- SD, 6.6 +/- 5.9 years). Laboratory, barium and endoscopic studies showed unspecific findings. Rheumatic and thyroid diseases as well as drug allergies were found in five cases. The cause of collagenous colitis and the mechanism of diarrhoea remains undefined, being the inflammatory and autoimmune hypothesis the most likely. Diagnosis was made by multiple rectal and colonic biopsies. Pathologic findings characteristic of CC were more prominent in proximal than in distal colonic specimens. Different treatments were applied and diverse clinic responses were obtained. A review of the literature is made.