Endoscopic Center, Osaka Medical College Hospital, Takatsuki, Japan. Center for Clinical Research, Hamamatsu University School of Medicine, Hamamatsu, Japan. Department of Gastroenterology, Osaka City University Graduate School of Medicine School of Medicine, Osaka, Japan. Division of Digestive Endoscopy, Shiga University of Medical Science Hospital, Otsu, Japan. Department of Gastroenterology, Aichi Medical University, Aichi, Japan. Department of Endoscopy and Endoscopic Surgery, Gunma University Hospital, Meabashi, Japan. Department of Gastroenterology and Hepatology, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan. First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan. Second Department of Internal Medicine, Osaka Medical College, Takatsuki, Japan. Department of Internal Medicine, Saga Medical School, Saga, Japan.