[1] McGill Univ, Div Gastroenterol, Ctr Hlth, Montreal, PQ H3G 1A4, Canada
[2] Erasmus MC Univ Med Ctr, Dept Gastroenterol & Hepatol, Rotterdam, Netherlands
[3] Erasmus MC Univ Med Ctr, Dept Internal Med, Rotterdam, Netherlands
[4] Chinese Univ Hong Kong, Inst Digest Dis, Hong Kong, Hong Kong, Peoples R China