A 71-year-old woman with polymyalgia rheumatica developed diarrhea 6 months after starting lansoprazole (LPZ) and predonisolone. Colonoscopy was performed and showed numerous crowded blood vessels in the transverse and descending colon (Color 1) and a linear ulcer scar in the sigmoid colon (Color 2) . The pathologic examination of the biopsy specimen revealed thickening of the epithelial collagen layer, and intraepithelial infiltration with inflammatory cells. Ten days after she stopped LPZ, the diarrhea ceased. Therefore her disease was diagnosed as a LPZ-associated collagenous colitis.
A 67-year-old man with reflux esophagitis developed diarrhea 7 months after starting lansoprazole (LPZ) . Colonoscopy was performed and showd numerous crowded blood vessels in the ascending and transverse colon. The pathologic examination of the biopsy specimen revealed thickening of the epithelial collagen layer, and intraepitherial infiltration with inflammatory cells. His disease was daiagnosed as a collagenous colitis.
In addition, we analyzed the colonoscopic findings of our experienced 12 cases of collagenous colitis including the two cases in 2009 and 2010. The results were summarized in Table 1.
