[1] Hosp Univ Princesa, Gastroenterol Unit, Inst Invest Sanitaria Princesa, CIBEREHD, Madrid, Spain
[2] Seconda Univ Napoli, Naples, Italy
[3] Osped PO Immacolata, Sapri, Italy
[4] Angloamer Med Unit, Madrid, Spain
[5] Hosp Fuenlabrada, Madrid, Spain
[6] Hosp San Pedro de Alcantara, Caceres, Spain
[7] Hosp Valme, Seville, Spain
[8] CIBEREHD, Madrid, Spain
[9] Hosp La Fe, E-46009 Valencia, Spain
[10] Hosp Gen Tomelloso, Ciudad Real, Spain
[11] Hosp N Sra Sonsoles, Avila, Spain
[12] Consorci Sanitari Terrassa, Barcelona, Spain
[13] Hosp Don Benito, Badajoz, Spain
[14] Hosp Gregorio Maranon, Madrid, Spain
[15] Hosp Rio Hortega, Valladolid, Spain
[16] Hosp Clin, Valladolid, Spain
[17] Hosp Quiron Sagrado Corazon, Seville, Spain
[18] Alto Guadalquivir, Jaen, Spain