1. Department of Internal Medicine, San Matteo Hospital Foundation, Pavia, Italy
2. Gastroenterology and Endoscopy Unit, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico and Università degli Studi di Milano, Milan, Italy
3. Department of Internal Medicine, University of Pavia, Pavia, Italy
4. Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico of Milan, Milan, Italy
5. Gastroenterology Unit, Valduce Hospital, Como, Italy
6. Gastroenterology Unit, Spedali Civili di Brescia and Department of Clinical and Experimental Sciences, University of Brescia, Brescia Italy
7. Sacco, University of MilanGastroenterology and Digestive Endoscopy Unit, Department of Biochemical and Clinical Sciences L , Milano, Italy