1. Department of Gastroenterology, Inflammatory Bowel Disease Unit, Hospital Clínico San Carlos and Instituto de Investigación del Hospital Clínico San Carlos (IdISSC), Madrid, Spain;
2. Department of Gastroenterology and CIBERehd, Hospital Universitario La Fe, Valencia, Spain;
3. Department of Gastroenterology, Inflammatory Bowel Disease Unit, Hospital Clínico de Valencia, Valencia, Spain;
4. Department of Gastroenterology, Complejo Hospitalario de Navarra and Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain;
5. Department of Gastroenterology, Hospital Urduliz, Vizcaya, Spain;
6. Department of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain;
7. Department of Gastroenterology, Hospital 12 de Octubre, Madrid, Spain;
8. Department of Gastroenterology, Hospital de León, León, Spain;
9. Department of Gastroenterology, Hospital Universitario Infanta Sofía, San Sebastián de los Reyes, Madrid, Spain;
10. Department of Gastroenterology, Hospital Universitario Fundación Alcorcón, Madrid, Spain;
11. Department of Gastroenterology, Hospital Universitario de Fuenlabrada, Madrid, Spain