Abstract
A 68-year-old woman was admitted to our hospital with a one-month history of continuous watery diarrhea. The patient had been taking various medications including lansoprazole for more than six months. On colonoscopy, multiple longitudinal, thin ulcers were noted on the left side of the colon. Multiple biopsy specimens obtained from each segment of the large intestine were found to have thickened subepithelial collagen bands, which measured more than 30μm in thickness. The patients clinical and histological findings were compatible with the diagnosis of collagenous colitis. After discontinuing lansoprazole, the patients symptom improved. One year later, her colonic lesions were found to have healed completely.
