1. Department of Gastrointestinal Surgery; Graduate School of Medicine; The University of Tokyo; Tokyo Japan
2. Department of Gastroenterology; Murakami Memorial Hospital; Asahi University; Gifu Japan
3. Division of Gastroenterology; Kyoto Min-iren Chuo Hospital; Kyoto Japan
4. Department of Clinical Nursing; Faculty of Medicine; Shimane University; Matsue Japan
5. Niigata University; Niigata Japan
6. Department of Clinical Research and Informatics; International Clinical Research Center; Research Institute; International Medical Center of Japan; Tokyo Japan