[Diarrhea].

A 54-year-old man had recurrent watery diarrhea with up to 10 stools per day for 4 years. The initial evaluation including coloscopy did not disclose a pathologic finding. The symptoms subsided initially after four weeks. Three years later massive watery diarrhea recurred with up to fifteen daily stools. A reevaluation of the patient disclosed the diagnosis of collagen colitis in the colonic biopsy.