1. Division of Gastroenterology, Department of Medicine and Surgery, University of Milano-Bicocca, Milano, Italy
2. Gastroenterology Unit, Valduce Hospital, Como, Italy
3. Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Department of Gastroenterology and Hepatology, University of Milan, Milan, Italy
4. Gastrointestinal Unit, Department of Medicine, Surgery & Dentistry Scuola Medica Salernitana, University of Salerno, Salerno, Italy