1. Gastroenterology Unit, University of Salerno, Italy
2. Gastroenterology and Endoscopy Unit, L. Curto Hospital, Polla, Italy
3. Gastroenterology Unit, Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy
4. Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy
5. Division of Surgical Digestive System, University Hospital Second University of Naples, Italy