[1] Univ Michigan, Med Ctr, Div Gastroenterol, Ann Arbor, MI 48109 USA
[2] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON, Canada
[3] Sahlgrens Univ Hosp, Dept Mol & Clin Med, Gothenburg, Sweden
[4] Univ Sydney, Dept Gastroenterol, Concord Hosp, Sydney, NSW 2006, Australia
[5] Univ Hosp, Dept Med, I CS CIBERehd, Zaragoza, Spain
[6] Univ Alberta, Dept Med, Div Gastroenterol, Edmonton, AB, Canada
[7] AstraZeneca R&D, Molndal, Sweden