1. Department of Gastroenterology, IRCCS Istituto Clinico Humanitas, Milan, Italy
2. Department of Gastroenterology, University Hospital L. Sacco, Milan, Italy
3. Department of Gastroenterology, University Hospital, Messina, Italy
4. Department of Internal Medicine, Genoa University, Genoa, Italy
5. Department of Gastroenterology, IRCCS Istituto Clinico Humanitas, Bergamo, Italy
6. Department of Gastroenterology, “La Sapienza” University Hospital, Roma, Italy