1. Section of Gastroenterology; DI.BI.M.I.S.; Palermo Italy
2. Unit of Infectious Diseases and Hepatology; Teaching Hospital-University of Parma; Italy
3. Division of Internal Medicine 2; Ospedali Riuniti Villa Sofia-Cervello; Palermo Italy
4. Division of Gastroenterology; Belcolle Hospital; Viterbo Italy
5. Division of Internal Medicine; Department of Medical and Surgical Sciences; Alma Mater Studiorum; Bologna Italy
6. Division of Gastroenterology; Department of Medicine and Surgery; University of Naples Federico II; Italy
7. Department of Medical and Surgical Sciences; University of Bologna; Italy
8. Department of Surgery; Oncology and Gastroenterology; University of Padua Italy
9. Gastroenterology Unit; Department of Internal Medicine; IRCCS Azienda Ospedaliera Universitaria San Martino IST; Genoa Italy
10. Division of Semeiotics; Department of Medical and Surgical Sciences; Alma Mater Studiorum; Bologna Italy
11. Humanitas Clinical and Research Center; Rozzano Italy