[1] Kyushu Univ, Grad Sch Med Sci, Dept Med & Clin Sci, Fukuoka 8128582, Japan
[2] Osaka City Univ, Grad Sch Med, Dept Gastroenterol, Osaka 558, Japan
[3] Kyoto Prefectural Univ Med, Kyoto 602, Japan
[4] Kyoto Univ, Grad Sch Med, Dept Gastroenterol & Hepatol, Kyoto, Japan
[5] Keio Univ, Sch Med, Dept Internal Med, Div Gastroenterol & Hepatol, Tokyo 108, Japan
[6] Tokyo Med & Dent Univ, Sch Med, Dept Gastroenterol, Tokyo 113, Japan
[7] Hyogo Coll Med, Dept Internal Med, Div Lower Gastroenterol, Nishinomiya, Hyogo 6638501, Japan
[8] Osaka Med Coll, Dept Internal Med 2, Takatsuki, Osaka 569, Japan
[9] Nagoya Univ, Grad Sch Med, Dept Gastroenterol, Nagoya, Aichi 4648601, Japan
[10] Sapporo Kosei Gen Hosp, Div Gastroenterol, Sapporo, Hokkaido, Japan