1. Paediatric Surgery Unit, University of Padova, Via Giustiniani 3, 35128 Padova, Italy
2. Gastroenterology and Digestive Endoscopy Unit, NiguardaCa' Granda Hospital, Milan, Italy
3. Poison Control Centre, Bergamo, Italy
4. Pediatric Gastroenterology Division, La Sapienza University, Rome, Italy
5. Airways Endoscopic Surgery Unit, Padova General Hospital, Padua, Italy
6. Digestive Surgery and Endoscopy Unit, Ospedale Pediatrico Bambino Gesù, Rome, Italy
7. Pediatric Gastroenterology and Endoscopic Unit, University of Parma, Parma, Italy
8. Pediatric Surgery Unit, Niguarda Ca' Granda Hospital, Milan, Italy
9. Pediatric Gastroenterology, G Gaslini Institute, Genoa, Italy
10. Paediatric Gastroenterology Unit, Spirito Santo Hospital, Pescara, Italy
11. Paediatric Department, University of Messina, Messina, Italy