[1] FMU, Aizu Med Ctr, Coloproctol & Gastroenterol, Aizu Wakamatsu, Fukushima, Japan
[2] Univ Aizu, Aizu Wakamatsu, Fukushima, Japan
[3] Otaru Ekisaikai Hosp, Otaru, Hokkaido, Japan
[4] Jichi Med Univ, Shimotsuke, Tochigi, Japan
[5] Univ Queensland, Sch Med, Brisbane, Qld, Australia