[1] Sapporo Higashi Tokushukai Hosp, IBD Ctr, Sapporo, Hokkaido 0650033, Japan
[2] Asahikawa Med Coll, Dept Internal Med 3, Asahikawa, Hokkaido 078, Japan
[3] Hirosaki Univ, Sch Medicine, Dept Internal Med 1, Hirosaki, Aomori, Japan
[4] Sendai Social Insurance Hosp, Dept Gastroenterol, Sendai, Miyagi, Japan
[5] Tokyo Womens Med Univ, Inst Gastroenterol, Tokyo, Japan
[6] Showa Univ, Fujigaoka Hosp, Div Gastroenterol, Tokyo, Japan
[7] Hamamatsu Univ Sch Med, Dept Endoscop & Photodynam Med, Hamamatsu, Shizuoka, Japan
[8] Kyoto Prefectural Univ Med, Dept Med, Kyoto 602, Japan
[9] Hyogo Coll Med, Dept Internal Med, Div Lower Gastroenterol, Nishinomiya, Hyogo, Japan
[10] Kobe Univ Hosp, Dept Endoscopy, Kobe, Hyogo, Japan
[11] Fukuoka Univ, Chikushi Hosp, Dept Gastroenterol, Fukuoka, Japan
[12] Kurume Univ, Sch Med, Dept Med, Div Gastroenterol, Kurume, Fukuoka, Japan
[13] Keio Univ, Sch Med, Dept Internal Med, Tokyo 108, Japan