1. Department of Surgical, Oncological and Gastroenterological Sciences; University of Padua; Padua Italy
2. Department of Internal Medicine; University of Genoa; Genoa Italy
3. Università degli Studi di Milano and Fondazione IRCCS Cà Granda - Ospedale Maggiore Policlinico Scienze Mediche; Milan Italy
4. Division of Gastroenterology; Johns Hopkins University; Baltimore Maryland
5. Department of Gastroenterology; Saint Andre Hospital; Bordeaux France
6. Izmir Training and Research Hospital; Izmir; Turkey