1. Gastroenterology, Hospital San Eloy, Barakaldo, Spain
2. Gastroenterology, Clinica Universidad de Navarra, Spain
3. Endoscopy Unit. Gastroenterology Dpt., Hospital Universitario Miguel Servet, Zaragoza, Spain
4. Digestive Endoscopy Unit, Gastrointestinal Endoscopy Research Group, IIS Hospital La Fe, Hospital Universitari i Politecnic La Fe, Valencia, Spain
5. Gastroenterology/Endoscopy, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
6. Gastroenterology, Hospital Clínico San Carlos, Madrid, Spain
7. Endoscopy Unit, Hospital General Universitari d'Alacant, Alicante, Spain
8. Unidad de Gestion Clinica de Digestivo, Hospital Clinico Universitario Virgen de la Arrixaca, El Palmar, Spain
9. Gastroenterology, HU Morales Meseguer, Murcia, Spain
10. Aparato Digestivo, Hospital Universitario Fundacion Jimenez Diaz, Madrid, Spain
11. Gastroenterology, Hospital Clinic Universitari de Valencia, Valencia, Spain
12. Gastroenterology, Hospital Universitario de Toledo, Toledo, Spain
13. Dept. of Gastroenterology, HGU Gregorio Marañon, Madrid, Spain
14. Servicio de Gastroenterología, Hospital Clínic de Barcelona ICMiD, Barcelona, Spain
15. Gastroenterology, Virgen Macarena University Hospital, Seville, Spain
16. Gastroenterology, Consorcio Hospital General Universitario de Valencia, Valencia, Spain
17. Gastroenterology, Hospital Universitario Ramon y Cajal, Madrid, Spain
18. Gastroenterology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
19. Dept. of Gastroenterology, Hospital Universitario Nuestra Señora de la Candelaria, Santa Cruz de Tenerife, Spain
20. Gastroenterology, Complexo Hospitalario Universitario A Coruña, A Coruna, Spain
21. Gastroenterology Department, Hospital Clinic de Barcelona, Barcelona, Spain
22. IDIBAPS, Barcelona, Spain