1. Center for Diagnostic and Therapeutic Endoscopy, School of Medicine, Keio University, Tokyo, Japan
2. Department of Gastroenterology, School of Medicine, Fujita Health University, Aichi, Japan
3. Department of Gastroenterology, Fukuoka University Chikushi Hospital, Chikushino, Japan
4. Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
5. Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan
6. Department of Gastroenterology and Hepatology, Sapporo Medical University School of Medicine, Sapporo, Japan
7. Department of Medicine, Shiga University of Medical Science, Otsu, Japan
8. Department of Gastroenterology, Saitama Medical University, Saitama, Japan
9. Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Iwate Medical University, Morioka, Japan
10. The third Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan