[1] IRCCS Policlin San Donato, Gastroenterol & Digest Endoscopy Unit, Milan, Italy
[2] Allgemeines Krankenhaus Celle, Klin Gastroenterol GI Onkol, Celle, Germany
[3] AO Lodi, Gastroenterol & Digest Endoscopy Unit, Lodi, Italy
[4] Royal Hallamshire Hosp, Gastroenterol, Sheffield, S Yorkshire, England
[5] Valduce Hosp, Gastroenterol, Como, Italy
[6] Royal Infirm Edinburgh NHS Trust, Ctr Liver & Digest Disorders, Edinburgh, Midlothian, Scotland
[7] Univ Milan, IRCCS Policlin San Donato, Gastroenterol & Digest Endoscopy Unit, Milan, Italy