Abstract
A 73-year-old woman, who had been receiving continuous ambulatory peritoneal dialysis (CAPD) for chronic renal failure due to nephrosclerosis since 2007, was admitted to our hospital for CAPD peritonitis. Treatment was started with intravenous cefazolin and ceftazidime, which was later administered intraperitoneally for 2 weeks. After hospital discharge, she had chronic non-bloody watery diarrhea. Clostridium difficile antigen, as detected in her watery stool, was treated with metronidazole for 2 weeks. However, her diarrhea symptoms did not improve, appetite loss occurred, and the inflammatory reaction became positive. She was admitted again for further examination to determine the cause of the diarrhea. On colon fiberscopy, her colon appeared normal. Histopathological examination, however, revealed a thickened sub-epithelial collagen band in the chronic mucosa, and a definitive diagnosis of collagenous colitis (CC) was made. CC is characterized by chronic watery diarrhea without bleeding. Recently, the number of patients with CC has been increasing in Japan. CC has often been linked to the use of non-steroidal anti-inflammatory drugs (NSAIDs), lansoprazole, simvastatin, and other drugs. In this case, lansoprazole was started 3 months before the onset of diarrhea symptoms. As lansoprazole could be a cause, it was discontinued, and then her diarrhea symptoms disappeared. Many patients on dialysis use proton pump inhibitors to prevent and treat peptic ulcers. CC, however, has seldom been reported in patients on CAPD. In conclusion, CC should be suspected if chronic watery diarrhea of unknown origin is encountered in CAPD patients, such as in the present case.
