1. Gastrointestinal Unit; Department of Surgery; University of Pisa; Pisa Italy
2. Institute of Clinical Physiology; CNR; Pisa Italy
3. Gastroenterology and Endoscopy Unit; Malatesta Novello Hospital; Cesena Italy
4. Department of Surgery and Translational Medicine; University of Florence; Florence Italy
5. Gastroenterology and Endoscopy Unit; Department of Gastroenterology; AORN A. Cardarelli; Naples Italy
6. Digestive Endoscopy Unit; Lucca Hospital; Lucca Italy
7. Gastroenterology and Endoscopy Unit; Cardinal Massaja Hospital; Asti Italy
8. Gastroenterology and Hepatology Section; Department of Medicine; University of Perugia; Perugia Italy