1. Pediatric Surgery Department, Hospital Clínico Universitario de Santiago de Compostela
2. Pediatric Gastroenterology Department, Hospital Universitario Virgen Macarena, Seville
3. Pediatric Gastroenterology Unit, Hospital de Tarrasa, Barcelona
4. Pediatric Department, Policlínico Vigo, Povisa, Vigo
5. Pediatric Gastroenterology Unit, Centro Infantil do Norte, Oporto
6. Pediatric Gastroenterology Department, Hospital Sao Joao, Oporto.