[1] King Saud Univ, King Khalid Univ Hosp, Div Gastroenterol, Riyadh, Saudi Arabia
[2] McGill Univ, McGill Univ Hlth Ctr, Montreal Gen Hosp, Div Gastroenterol, Montreal, PQ H3G 1A4, Canada
[3] McGill Univ, McGill Univ Hlth Ctr, Montreal Gen Hosp, Div Clin Epidemiol, Montreal, PQ, Canada
[4] Kuwait Univ, Fac Med, Dept Med, Jabriyah, Kuwait