[1] McGill Univ, Hlth Ctr, Div Gastroenterol & Hepatol, Montreal, PQ, Canada
[2] Jewish Gen Hosp, Div Gastroenterol, Montreal, PQ, Canada
[3] Univ Hosp Geneva, Gastroenterol Dept, Geneva, Switzerland
[4] Semmelweis Univ, Dept Med 1, Budapest, Hungary
[5] McGill Univ, Royal Victoria Hosp, Chron Viral Illness Serv, Div Gastroenterol & Hepatol,Hlth Ctr, 1001 Blvd Decarie, Montreal, PQ H4A 3J1, Canada