[1] Complejo Hosp Navarra, Pamplona, Spain
[2] Hosp Univ Clin, Barcelona, Spain
[3] Hosp Univ Canarias, Tenerife, Spain
[4] Hosp Gen Tomelloso, Ciudad Real, Spain
[5] Complejo Hosp Univ A Coruna, La Coruna, Spain
[6] Hosp Univ Puerta de Hierro, Madrid, Spain
[7] Hosp Mar, Barcelona, Spain
[8] Hosp San Pedro, Logrono, Spain
[9] Clin Univ Navarra, Pamplona, Spain
[10] Hosp Univ Lucus Augusti, Lugo, Spain
[11] Complejo Hosp Vigo, Vigo, Pontevedra, Spain
[12] Hosp Univ Virgen Arrixaca, Murcia, Spain
[13] Nottingham Digest Dis Biomed Res Unit, Nottingham, England
[14] Hosp Univ Virgen Nieves, Granada, Spain
[15] Hosp Costa del Sol, Malaga, Spain
[16] Complejo Hosp Ourense, Orense, Spain
[17] Hosp Univ 12 Octubre, Madrid, Spain
[18] Hosp Univ Virgen Macarena, Seville, Spain
[19] Hosp Moises Broggi, Barcelona, Spain
[20] Hosp Clin Univ Lozano Blesa, Zaragoza, Spain
[21] Hosp Gen Cataluna, Barcelona, Spain
[22] Hosp Univ HM Monteprincipe, Madrid, Spain
[23] EuropaColon Espana, Madrid, Spain
[24] Hosp Univ & Politecn La Fe, Valencia, Spain
[25] Hosp Univ Doctor Josep Trueta, Girona, Spain
[26] Hosp Santa Creu & Sant Pau, Barcelona, Spain
[27] Hosp Univ Donostia, Donostia San Sebastian, Guipuzcoa, Spain
[28] Hosp Gen Ciudad Real, Ciudad Real, Spain
[29] Hosp Gen Univ Gregorio Maranon, Madrid, Spain
[30] Hosp Valdecilla, Santander, Spain
[31] Complejo Hosp Toledo, Toledo, Spain
[32] Hosp Reina Sofia, Navarra, Spain
[33] Hosp Univ Clin San Carlos, Madrid, Spain
[34] Ctr Andaluz Gastroenterol Integral, Seville, Spain