1 Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan. hxnwq178@yahoo.co.jp.
2 Department of Internal Medicine, Sumitomo Bessi Hospital, Niihama, 792-8543, Japan.
3 Department of Gastroenterology, National Hospital Organization, Fukuyama Medical Center, Fukuyama, 720-8520, Japan.
4 Department of Gastroenterology, Tsuyama Chuo Hospital, Tsuyama, 708-0841, Japan.
5 Department of Internal Medicine, Okayama Saiseikai General Hospital, Okayama, 700-8551, Japan.
6 Department of Internal Medicine, Hiroshima City Hospital, Hiroshima, 730-8518, Japan.
7 Department of Internal Medicine, Kurashiki Central Hospital, Kurashiki, 710-8602, Japan.
8 Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
9 Department of Internal Medicine, Japanese Red Cross Society Himeji Hospital, Himeji, 670-8540, Japan.
10 Department of Internal Medicine, Okayama City Hospital, Okayama, 700-0833, Japan.
11 Department of Endoscopy, Okayama University Hospital, Okayama, 700-8558, Japan.