1. Department of Gastroenterology and Hepatology; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan
2. Department of Gastroenterology; Fukuyama Medical Center; Fukuyama Japan
3. Department of Internal Medicine; Fukuyama City Hospital; Fukuyama Japan
4. Department of Internal Medicine; Tsuyama Chuo Hospital; Tsuyama Japan