[1] Sultan Qaboos Univ, Coll Med & Hlth Sci, Dept Med, POB 35, Muscat 123, Oman
[2] McGill Univ Hlth Ctr, Royal Victoria Hosp, Dept Gastroenterol, Montreal, PQ H3A 1A1, Canada
[3] McGill Univ Hlth Ctr, Royal Victoria Hosp, Dept Med, Montreal, PQ H3A 1A1, Canada
[4] McGill Univ, Jewish Gen Hosp, Dept Gastroenterol, Montreal, PQ, Canada