1. Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan
2. Department of Gastroenterology, Iwakuni Clinical Center, Japan
3. Department of Internal Medicine, Okayama Saiseikai General Hospital, Japan
4. Department of Gastroenterology, Mitoyo General Hospital, Japan
5. Department of Internal Medicine, Hiroshima City Hospital, Japan
6. Department of Internal Medicine, Tsuyama Central Hospital, Japan
7. Department of Gastroenterology, Fukuyama Medical Center, Japan
8. Department of Internal Medicine, Ibara City Hospital, Japan
9. Department of Surgery, Onomichi Municipal Hospital, Japan
10. Department of Gastroenterology, Onomichi Municipal Hospital, Japan
11. Department of Endoscopy, Okayama University Hospital, Japan