Division of Gastroenterology;
University of Pisa;
56124 Pisa;
Italy;
Ear;
Nose and Throat Audiology Phoniatrics Unit;
University of Pisa;
56124 Pisa;
Italy;
Division of Gastroenterology;
University of Padua;
35100 Padua;
Italy;
Division of Gastroenterology;
University of Genoa;
16100 Genoa;
Italy;