[1] Univ Calgary, Div Gastroenterol & Hepatol, Calgary, AB, Canada
[2] Robarts Clin Trials, London, ON, Canada
[3] Univ Med Ctr, Dept Gastroenterol & Hepatol, Amsterdam UMC, Meibergdreef 9, NL-1105 AZ Amsterdam, Netherlands
[4] Univ Calif San Diego, Div Gastroenterol, La Jolla, CA 92093 USA
[5] Western Univ, Dept Epidemiol & Biostat, London, ON, Canada
[6] Imelda Gen Hosp, Imelda Gastrointestinal Clin Res Ctr, Bonheiden, Belgium
[7] Univ Hosp Leuven, Div Gastroenterol & Hepatol, Leuven, Belgium
[8] Western Univ, Dept Med, Div Gastroenterol, London, ON, Canada