[1] HOSP UNIV GERMANS TRIAS I PUJOL, DEPT GASTROENTEROL, E-08916 BARCELONA, SPAIN
[2] HOSP SANT LLORENC, DEPT GASTROENTEROL, VILADECANS, SPAIN
[3] HOSP JOSEP TRUETA, DEPT GASTROENTEROL, GIRONA, SPAIN
[4] CIUTAT SANITARIA UNIV BELLVITGE, DEPT SURG, LHOSPITALET DE LLOBREGAT, SPAIN
[5] CIUTAT SANITARIA UNIV BELLVITGE, DEPT PATHOL, LHOSPITALET DE LLOBREGAT, SPAIN