1. Department of Digestive Diseases, Hospital del Mar, Barcelona, Spain
2. Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
3. IMIM, Hospital del Mar Medical Research Institute, Barcelona, Spain
4. Department of Digestive Diseases, Hospital Universitario de Burgos, Burgos, Spain
5. Department of Digestive Diseases, Hospital de Viladecans, Barcelona, Spain
6. Department of Digestive Diseases, Hospital Santa Bárbara, Soria, Spain
7. Department of Digestive Diseases, Hospital Gregorio Marañón, Madrid, Spain
8. Department of Digestive Diseases, Hospital del Rio Hortega, Valladolid, Spain
9. Department of Digestive Diseases, Altahia Xarxa Asistencial Universitaria de Manresa, Barcelona, Spain
10. Department of Digestive Diseases, Consorci Sanitari de Terrassa, Barcelona, Spain
11. Department of Digestive Diseases, Hospital Germans Trias i Pujol, Badalona, Spain
12. Department of Digestive Diseases, Hospital 12 de Octubre, Madrid, Spain
13. Department of Digestive Diseases, Hospital Universitario de Canarias, La Laguna, Spain
14. Open University of Catalonia, Barcelona, Spain