[1] Univ Tampere, Sch Med, Dept Gastroenterol & Alimentary Tract Surg, FIN-33210 Tampere, Finland
[2] Univ Milan, IRCCS Ca Granda Osped Maggiore Policlin Fdn, Gastroenterol Unit 3, Dept Med Sci, Milan, Italy
[3] Catholic Univ, Digest Endoscopy Unit, Rome, Italy
[4] Univ Oslo, Rikshosp, Oslo Univ Hosp, Endoscopy Unit,Dept Med,Ctr Immune Regulat, N-0027 Oslo, Norway
[5] Asklepios Klin Altona, Hamburg, Germany
[6] Vrije Univ Amsterdam, Dept Gastroenterol, Med Ctr, Small Bowel Unit, Amsterdam, Netherlands