The research deals with the study of respiratory function in adequate postoperative pain management of patients operated on rectal cancer. 120 patients (age range 45-69) were observed during the research. The patients were divided in II groups. I group (=30) was given multicomponent IV analgesia (propofol+fentanil) with total muscle relaxation (atracurium besylate), assisted ventilation and postoperative opiate painkilling. II group (n=60) was given monosegmental spinal and epidural anesthesia followed by induction (propofol+atracurium besylate), assisted ventilation and postoperative epidural analgesia with ropivacaine. The results indicate the advantage of epidural analgesia with ropivacaine, which provides better psychological and emotional background, prevents negative pulmonary manifestations and facilitates fast and comfortable intestinal peristalsis resumption.