Hiroki Matsuura1, Shinichiro Muro2, Kenji Yamauchi3. 1. Department of General Internal Medicine, Mitoyo General Hospital, Kanonji-city, Kagawa, Japan. Electronic address: superonewex0506@yahoo.co.jp. 2. Department of Gastroenterology and Hepatology, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan. 3. Department of Gastroenterology, Mitoyo General Hospital, Kanonji-city, Kagawa, Japan.