1. Gastroenterology and Endoscopy Unit, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
2. Department of Internal Medicine and Medical Therapeutics, University of Pavia, 27100 Pavia, Italy
3. First Department of Internal Medicine, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
4. Gastroenterology Unit, Department of Medical and Surgical Sciences, University of Foggia, Viale Luigi Pinto 1, 71122 Foggia, Italy
5. General Surgery I, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy