1. Gastroenterology Unit, University of Pisa, Pisa, Italy
2. Gastroenterology Unit, University of Pisa, and Cisanello Hospital, Via Paradisa 2 – 56124 Pisa (PI), Italy
3. Division of Gastroenterology, University of Padua, Padua, Italy
4. Ear, Nose and Throat Audiology Phoniatrics Unit, University of Pisa, Pisa, Italy
5. Division of Gastroenterology, Department of Internal Medicine (DIMI), University of Genoa, Genoa, Italy