1. Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
2. Department of Gastroenterology and Hepatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
3. Department of Gastroenterology, Gifu Municipal Hospital, Gifu, Japan
4. First Department of Internal Medicine, Gifu University Hospital, Gifu, Japan
5. Department of Gastroenterology, Teikyo University Mizonokuchi Hospital, Kanagawa, Japan
6. Department of Gastroenterology, Nagoya Daini Red Cross Hospital, Nagoya, Japan
7. Department of Gastroenterology and Hepatology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
8. Department of Gastroenterology, Japanese Red Cross Medical Center, Tokyo, Japan
9. Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, Sapporo, Japan
10. Department of Gastroenterology, Tokyo Takanawa Hospital of Japan Community Health-care Organization, Tokyo, Japan
11. Division of Gastroenterology, Yokohama City University, Graduate School of Medicine, Yokohama, Japan
12. Department of Gastroenterology, Kanto Central Hospital, Tokyo, Japan
13. Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
14. Division of Gastroenterology, Department of Medicine, Kurume University of Medicine, Kurume, Japan
15. Department of Gastroenterology, Tokyo Metropolitan Police Hospital, Tokyo, Japan
16. Department of Gastroenterology and Hepatology, Saitama Medical Center, Saitama Medical University, Saitama, Japan
17. Department of Gastroenterology, JR Tokyo General Hospital, Tokyo, Japan
18. Department of Gastroenterology, Graduate School of Medicine, Juntendo University, Tokyo, Japan