[1] Mayo Clin, Div Gastroenterol & Hepatol, Rochester, MN USA
[2] Univ Calif Davis, Div Rheumatol Allergy & Clin Immunol, Davis, CA 95616 USA
[3] Hosp St Antoine, Paris, France
[4] Tufts Med Ctr, Div Gastroenterol, Boston, MA USA
[5] Metropolitan Hosp Ctr, Dept Med, New York, NY 10029 USA
[6] Univ Toronto, Toronto Western Hosp, Toronto, ON M5T 2S8, Canada