1. Azienda Ospedaliero-Universitaria di Modena Ospedale Civile di Baggiovara, Gastroenterology and Digestive Endoscopy Unit, Modena, Italy
2. University of Naples Federico II, Department of Clinical Medicine and Surgery, Gastroenterology Unit, Naples, Italy
3. Azienda Ospedaliera di Perugia, Gastroenterology and Digestive Endoscopy Unit, Perugia, Italy