The authors report two cases of retroperitoneal fibrosis secondary to rectal perforation occurring during barium enema. In view of the variable interval between the radiological accident and the urological complications, a long patient follow-up is recommended. If ureteric obstruction occurs, ureteric catheterisation is a temporary alternative, but surgery is the treatment of choice. When ureterolysis cannot be performed, the authors propose ureteroileoplasty to restore continuity of the urinary tract