1. Gastroenterology Unit, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56125 Pisa, Italy
2. Division of Gastroenterology, Department of Surgery, Oncology and Gastroenterology, University of Padua, 35128 Padua, Italy
3. Gastroenterology Unit, Azienda Ospedale University of Padua, 35128 Padua, Italy
4. Division of Gastroenterology, Department of Internal Medicine, University of Genoa, 16132 Genoa, Italy