[1] Juntendo Univ, Sch Med, Dept Gastroenterol, Bukyo Ku, Tokyo 1138421, Japan
[2] Tokyo Metropolitan Komagome Hosp, Dept Internal Med, Tokyo, Japan
[3] Jichi Med Sch, Dept Internal Med, Div Gastroenterol, Minami Kawachi, Tochigi, Japan
[4] Tohoku Univ, Grad Sch Med, Dept Gastroenterol, Sendai, Miyagi 980, Japan
[5] Osaka City Univ, Grad Sch Med, Dept Gastroenterol, Osaka, Japan
[6] Kure Kyosai Hosp, Dept Gastroenterol, Hiroshima, Japan
[7] Hokkaido Univ, Sch Med, Dept Endoscopy, Sapporo, Hokkaido 060, Japan
[8] Oita Med Univ, Dept Internal Med 2, Oita, Japan
[9] Iwate Med Univ, Dept Internal Med, Morioka, Iwate, Japan
[10] Wakayama Univ, Hlth Adm Ctr, Wakayama, Japan
[11] Tokyo Med & Dent Univ, Sch Med, Dept Internal Med 1, Tokyo 113, Japan
[12] Tokai Univ, Sch Med, Div Gen Internal Med, Kanagawa 2591100, Japan
[13] Kobe Univ, Sch Med, Dept Endoscopy, Kobe, Hyogo 650, Japan
[14] Kawasaki Med Sch, Dept Internal Med, Div Gastroenterol, Okayama, Japan
[15] Kyoto Univ Hosp, Dept Gastroenterol & Endoscop Med, Kyoto 606, Japan
[16] Nagoya Univ, Sch Med, Dept Internal Med 1, Aichi, Japan
[17] Natl Tokyo Med Ctr, Div Gastroenterol, Tokyo, Japan
[18] Nagoya City Univ, Grad Sch Med Sci, Dept Comprehens Med, Div Internal Med & Bioregulat, Aichi, Japan
[19] Fukui Med Sch, Dept Gastroenterol 2, Fukui, Japan
[20] Univ Tsukuba, Inst Clin Med, Dept Gastroenterol, Tsukuba, Ibaraki 305, Japan
[21] Keio Univ, Sch Med, Dept Internal Med, Tokyo, Japan
[22] Tokyo Womens Med Univ, Inst Geriatr, Tokyo, Japan
[23] Tokyo Med Univ, Dept Internal Med 4, Tokyo, Japan
[24] Hokkaido Univ, Grad Sch Med, Dept Gastroenterol, Sapporo, Hokkaido 060, Japan