[1] Tokyo Med Univ, Gastroenterol Endoscopy, Shinjuku Ku, 6-7-1 Nishishinjuku, Tokyo 1600023, Japan
[2] Tokyo Med Univ Hosp, Dept Gen Med & Primary Care, Shinjuku Ku, 6-7-1 Nishishinjuku, Tokyo 1600023, Japan
[3] Shinjuku NS Bldg Clin, Shinjuku Ku, 2-4-1 Nishishinjuku, Tokyo 1630820, Japan
[4] Shinjuku Mitsui Bldg Clin, Shinjuku Ku, 2-4-1 Nishishinjuku, Tokyo 1830410, Japan
[5] Int Catholic Hosp, Dept Internal Med, Shinjuku Ku, 2-5-1 Nakaochiai, Tokyo 1618521, Japan
[6] Tokyo Shinjuku Med Ctr, Dept Gastroenterol, Shinjuku Ku, 5-1 Tsukudo Cho, Tokyo 1620821, Japan
[7] Hiratsuka Gastroenterol Hosp Shinjuku Ctr Clin, Shinjuku Ku, 1-25-1 Nishishinjuku, Tokyo 1630690, Japan
[8] NTT Med Ctr Tokyo, Dept Gastroenterol, Shinagawa Ku, 5-9-22 Higashi Gotanda, Tokyo 1418625, Japan
[9] Tokyo Womens Med Univ Hosp, Dept Gastroenterol, Shinjuku Ku, 8-1 Kawada Cho, Tokyo 1628666, Japan