1 Department of Gastroenterology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, 3-1 Aoyama-cho, Kure, 737-0023, Japan. kuwai.toshio.ur@mail.hosp.go.jp.
2 Department of Gastroenterology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, 3-1 Aoyama-cho, Kure, 737-0023, Japan.
3 Gastroenterology Department, Dudley Group Hospitals, Birmingham City University, Birmingham, UK.