["Microscopic colitis" and collagenous colitis. Unusual explanation of diarrhea of unknown origin].

The article describes two female patients with severe diarrhoea. Both patients were suspected of having an organic diarrhoea syndrome and underwent extensive investigations. No specific diagnoses such as inflammatory bowel disease, pancreatic cholera, malabsorption and surreptitous ingestion of laxatives could be established. Histologic examination of biopsy specimens from apparently normal colon revealed microscopic changes characteristic of "microscopic colitis" in one of the patients, and of collagenous colitis in the other. The authors discuss similarities between these two microscopic abnormalities in colonic mucosa and their close association with chronic watery diarrhoea.