[1] Hosp Univ Ramon y Cajal, Dept Gen & Digest Surg, Div Coloproctol, Madrid, Spain
[2] Hosp Univ Doctor Josep Trueta, Div Coloproctol, Girona, Spain
[3] Hosp Univ Principe Asturias, Div Coloproctol, Alcala De Henares, Spain
[4] Hosp Univ Virgen del Rocio, Div Coloproctol, Seville, Spain
[5] Hosp Univ Marques Valdecilla, Div Coloproctol, Santander, Spain
[6] Hosp Univ 12 Octubre, Div Coloproctol, Madrid, Spain
[7] Univ Autonoma Barcelona, Hosp Univ Vall dHebron, Dept Colorectal Surg, Barcelona, Spain
[8] Hosp Univ Gregorio Maranon, Div Coloproctol, Madrid, Spain
[9] Hosp Univ La Fe, Dept Gen & Digest Surg, Div Coloproctol, Valencia, Spain
[10] Complejo Hosp Univ A Coruna, Div Coloproctol, La Coruna, Spain
[11] Hosp Univ Clin San Carlos, Div Coloproctol, Madrid, Spain
[12] Hosp Del Mar, Div Coloproctol, Barcelona, Spain
[13] Hosp Univ Donostia, Colorectal Surg Unit, San Sebastian, Spain
[14] Hosp Univ Cruces, Div Coloproctol, Baracaldo, Spain
[15] Hosp Univ Getafe, Div Coloproctol, Getafe, Spain
[16] Hosp Univ Fdn Jimenez Diaz, Div Coloproctol, Madrid, Spain
[17] Hosp Univ Son Espases, Div Coloproctol, Palma De Mallorca, Spain