1. Department of Internal Medicine, Gastroenterology Unit, Policlinico IRCCS "San Martino", University of Genoa, Genoa, Italy
2. Department of Gastroenterology, University College Hospital NHS Foundation Trust, London, United Kingdom
3. Interventional and Experimental Endoscopy (InExEn), Internal Medicine II, University Hospital Wuerzburg, Wuerzburg, Germany
4. Gastroenterology Unit, Hospital of Imola, University of Bologna, Bologna, Italy
5. Digestive Endoscopy Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCSS, Rome, Italy
6. Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy