Department of Gastroenterology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan. k-takimoto-kengo-1209-1209@y8.dion.ne.jp. Department of Gastroenterology, Uji Tokushukai Medical Center, Kyoto, Japan. k-takimoto-kengo-1209-1209@y8.dion.ne.jp. Department of Gastroenterology, Uji Tokushukai Medical Center, 145, Ishibashi, Makishima-cho, Uji-city, Kyoto, Japan. k-takimoto-kengo-1209-1209@y8.dion.ne.jp. Department of Gastrointestinal Oncology, Osaka International Cancer Institute, Osaka, Japan. Department of Gastroenterology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan. Department of Gastroenterology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan. Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan. Department of Gastroenterology, International Clinical Cancer Research Center, Kobe University Hospital, Kobe, Japan. Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan. Division of Endoscopy, Yokohama City University Medical Center, Yokohama, Japan. Department of Gastroenterology, Gifu University Hospital, Gifu, Japan. Department of Gastroenterology and Hepatology, Nagasaki University Hospital, Nagasaki, Japan. Department of Gastroenterology, Fukui Prefectural Hospital, Fukui, Japan. Department of Gastroenterology, Akita University Graduate School of Medicine, Akita, Japan. Department of Gastroenterology, Toranomon Hospital, Tokyo, Japan. Department of Gastroenterology, Shinonoi General Hospital, Nagano, Japan. Department of Gastroenterology, Gifu Prefectural General Medical Center, Gifu, Japan. Department of Internal Medicine, Shikoku Cancer Center, Ehime, Japan. Department of Gastroenterology, Chugoku Central Hospital, Fukuyama, Japan. Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan.