1. Neurogastroenterology and Motility Unit, Department of Gastroenterology, Great Ormond Street Hospital for Children, London, UK
2. Department of Woman and Child Health and Public Health, Public Health Area, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
3. Department of Medical and Surgical Sciences, Pediatric Unit, University Magna Graecia of Catanzaro, Catanzaro, Italy
4. Digestive Endoscopy and Surgery Unit, Bambino Gesù Children's Hospital - Research Institute IRCCS, Rome, Italy
5. Pediatric Department, University of Insubria, Hospital “F. Del Ponte”, Varese, Italy
6. Department of Pediatrics, A.O.R.N. Santobono-Pausilipon, Napoli, Italy
7. NESMOS Department, Faculty of Medicine and Psychology, Sapienza University of Rome, Pediatric Unit, Sant’Andrea University Hospital, Rome, Italy
8. Pediatric and Pediatric Emergency Unit, Children Hospital, AO SS Antonio e Biagio e C. Arrigo, Alessandria, Italy
9. A.O.U. Mater Domini, University Magna Graecia of Catanzaro, Catanzaro, Italy