[1] Univ Calgary, Div Gastroenterol, Calgary, AB, Canada
[2] Nottingham Univ Hosp NHS Trust, Natl Inst Hlth Res, Biomed Res Ctr Gastrointestinal & Liver Dis, Queens Med Ctr Campus, Nottingham, England
[3] Univ Nottingham, Nottingham Univ Hosp NHS Trust, Queens Med Ctr Campus, Nottingham, England
[4] Univ Ottawa, Sch Epidemiol Publ Hlth & Prevent Med, Inflammatory Bowel Dis Ctr, Childrens Hosp Eastern Ontario,Dept Pediat, Ottawa, ON, Canada
[5] Inst Clin Evaluat Sci, Ottawa, ON, Canada
[6] Univ Manitoba, Div Internal Med, Sect Gastroenterol, Winnipeg, MB, Canada
[7] Univ Birmingham, Inst Translat Med, Coll Med & Dent Sci, Birmingham, W Midlands, England