[1] Juntendo Univ, Grad Sch Med, Dept Gastroenterol, Tokyo 1138421, Japan
[2] Hiroshima Prefectural Hosp, Dept Gastroenterol Surg, Hiroshima 7348530, Japan
[3] Aomori Prefectural Cent Hosp, Dept Gastroenterol, Aomori 0300913, Japan
[4] Toho Univ, Dept Surg, Ohashi Med Ctr, Tokyo 1538515, Japan
[5] Hiroshima Univ Hosp, Gastrointestinal Endoscopy & Med, Hiroshima 7340037, Japan
[6] NHO Kure Med Ctr, Dept Gastroenterol, Hiroshima 7370023, Japan
[7] Chugoku Canc Ctr, Hiroshima 7370023, Japan
[8] Toho Univ, Dept Gen & Gastroenterol Surg, Omori Med Ctr, Tokyo 1438541, Japan
[9] Aichi Med Univ, Sch Med, Dept Gastroenterol, Nagakute 4801155, Japan
[10] Tokyo Metropolitan Tama Med Ctr, Dept Surg, Tokyo 1898511, Japan
[11] Fukushima Med Univ, Aizu Med Ctr, Dept Coloproctol, Fukushima 9693482, Japan
[12] Tokyo Womens Med Univ, Inst Gastroenterol, Dept Surg, Tokyo 1628666, Japan
[13] Tokyo West Tokushukai Hosp, Dept Gastroenterol, Tokyo 1960003, Japan
[14] Kurashiki Cent Hosp, Dept Gastroenterol & Hepatol, Okayama 7100052, Japan
[15] Chibahokusoh Hosp, Dept Gastroenterol Surg, Nippon Med Sch, Chiba 2701694, Japan
[16] Natl Hosp Org Disaster Med Ctr, Dept Gastroenterol, Tokyo 1900014, Japan