1. Department of Medical and Surgical Sciences, University of Bologna, Via Massarenti 9, 40138 Bologna, Italy
2. Gastroenterology Unit, IRCCS Azienda Ospedaliero—Universitaria di Bologna, 40138 Bologna, Italy
3. Esophagus and Stomach Organic Diseases Unit, IRCCS Azienda Ospedaliero—Universitaria di Bologna, 40138 Bologna, Italy