1 Azienda Provinciale per i Servizi Sanitari, Gastroenterology and Digestive Endoscopy Unit, Santa Chiara Hospital, Trento, Italy.
2 Azienda Provinciale per i Servizi Sanitari, Gastroenterology and Digestive Endoscopy Unit, Santa Chiara Hospital, Trento, Italy; Gastroenterology Unit, G.B. Grassi Hospital (ASL Roma 3), Rome, Italy.