1. Department of Gastroenterology and Hepatology; Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences; Okayama Japan
2. Department of Internal Medicine; Hiroshima City Hospital; Hiroshima Japan
3. Department of Internal Medicine; Kagawa Prefectural Central Hospital; Takamatsu Japan
4. Department of Internal Medicine; Ritsurin General Hospital; Takamatsu Japan
5. Department of Internal Medicine; Okayama Saiseikai General Hospital; Okayama Japan
6. Department of Internal Medicine; Mitoyo General Hospital; Kanonji Japan