1. Section of Gastroenterology, Department of Emergency and Organ Transplantation, University “Aldo Moro”, Piazza Giulio Cesare, B ari, Italy
2. Gastroenterology Unit, National Institute of Research for Gastroenterology “Saverio De Bellis”, Castellana Grotte, Bari, Italy
3. Digestive Endoscopy Unit, National Institute of Research “Casa Sollievo della Sofferenza”, San Giovanni Rotondo, Foggia, Italy