Cat scratch colon: An endoscopic finding suggesting collagenous colitis

Collagenous colitis is a chronic inflammatory disease of the colon of unknown etiology. Diagnosis is considered in the presence of non-bloody, watery diarrhea and is confirmed by microscopic examination of samples taken during colonoscopy. "Cat scratch" colon is a colonoscopic finding characterized by red mucosal scratches that can be found both in normal and pathological colon. We report the case of a woman who underwent colonoscopy for the investigation of profuse watery diarrhea. The endoscopic finding of "cat scratch" colon, in association with the clinical symptoms, set the suspicion of collagenous colitis, which was histologically confirmed.