1. Division of Surgery; Department of Surgery; Second University of Naples; Naples Italy
2. Division of Gastroenterology; Department of Surgery, Oncology and Gastroenterology; University of Padua; Padua Italy
3. Division of Gastroenterology; Department of Internal Medicine; University of Pisa; Pisa Italy
4. Digestive Physiology; Hospices Civils de Lyon; Lyon I University and Labtau, INSERM 1032; Lyon France
5. U.O. Chirurgia Generale; Department of Surgery, Oncology and Gastroenterology; University of Padua; Padua Italy
6. Division of Gastroenterology; Department of Internal Medicine; University of Genoa; Genoa Italy