[1] Chinese Univ Hong Kong, Inst Digest Dis, Hong Kong, Hong Kong, Peoples R China
[2] McGill Univ, Div Gastroenterol, Quebec City, PQ, Canada
[3] McGill Univ, Ctr Hlth, Quebec City, PQ, Canada
[4] Fourth Mil Med Univ, Xijing Hosp, Inst Digest Dis, Xian 710032, Peoples R China
[5] Erasmus MC, Dept Gastroenterol & Hepatol, Rotterdam, Netherlands
[6] Chinese Peoples Liberat Army Gen Hosp, Dept Gastroenterol & Hepatol, Beijing, Peoples R China