1. Gastroenterology Unit; Department of Internal Medicine; IRCCS-University Hospital San Martino-IST, University of Genoa; Genoa Italy
2. Gastroenterology Unit; Department of Surgical and Gastroenterological Sciences; University of Padua; Padua Italy
3. Division of Surgery; San Marco Polyclinic; Zingonia Italy
4. Internal Medicine Unit; Department of Gastroenterology and Internal Medicine; Alma Mater Studiorum-Univeristy of Bologna; Bologna Italy
5. Unit of Internal Medicine and Gastroenterology; Columbus Integrated Complex; Catholic University of Rome; Rome Italy
6. Division of Medicine; Bolognini Teaching Hospital; Seriate Italy
7. Operative Gastroenterology Unit; Belcolle Hospital; Viterbo Italy
8. Internal Medicine Unit; Department of Medical and Surgical Sciences; Alma Mater Studiorum-University of Bologna; Bologna Italy
9. Radiology Unit; Department of Medicine; Fatebenefratelli Hospital; Milan Milan Italy
10. Gastroenterology Unit; Biomedical Department of Internal and Specialty Medicine; University of Palermo; Palermo Italy
11. Gastroenterology Unit; Bolzano Regional Hospital; Bolzano Italy
12. Unit of Internal Medicine and Gastroenterology; Gemelli Polyclinic; Catholic University of Rome; Rome Italy
13. Operative Unit for Gastroenterology and Metabolic Diseases; Teaching Hospital-University of Pisa; Pisa Italy
14. Department of Internal Medicine; Faenza Hospital for the Infirm; Faenza Italy
15. Unit of Infectious Diseases and Hepatology; Teaching Hospital-University of Parma; Parma Italy
16. Gastroenterology Unit; Department of Clinical Medicine and Surgery; Federico II University of Naples; Naples Italy
17. Gastroenterology Clinic; Marche Polytechnic University; Ancona Italy
18. Internal Medicine Unit 2; Biomedical Department of Internal and Specialty Medicine; Villa Sofia-Cervello United Hospitals; Palermo Italy
19. Medical Semeiotics Unit; Department of Medical and Surgical Sciences; Alma Mater Studiorum-University of Bologna; Bologna Italy