1. Inflammatory Bowel Disease Unit, “Villa Sofia-Cervello” Hospital , Palermo , Italy
2. Inflammatory Bowel Disease Unit, Policlinico “G. Martino,” Messina , Italy
3. Gastroenterology and Hepatology Section, Promise, University of Palermo , Palermo , Italy
4. Inflammatory Bowel Disease Unit, “Cannizzaro” Hospital , Catania , Italy
5. Gastroenterology Unit, Policlinico “Vittorio Emanuele,” Catania , Italy
6. Gastroenterology Unit, A.R.N.A.S. “Garibaldi,” Catania , Italy
7. Gastroenterology and Endoscopy Unit, “Buccheri La Ferla Fatebenefratelli” Hospital , Palermo , Italy
8. Gastroenterology Unit, “Guzzardi” Hospital , Vittoria , Italy
9. Gastroenterology Unit, “S. Elia- M. Raimondi” Hospital , Caltanissetta , Italy
10. Gastroenterology Unit, “Papardo Piemonte” Hospital , Messina , Italy
11. Pediatric Gastroenterology and Cystic Fibrosis Unit, University of Messina , Messina , Italy
12. Pediatric Unit, “Villa Sofia-Cervello” Hospital , Palermo , Italy