Objective: The aim of this study was to improve the direct results of reconstructive surgery in patients operated on for complicated forms of colorectal cancer, by using 5-fluorouracil in the postoperative period. Methods: The study involved 126 patients (they were divided into 2 groups) with colorectal cancer, who underwent reconstructive surgery. They underwent a standard clinical examination and a mandatory examination program. Results: The use of 5-fluorouracil in adjuvant treatment in patients with colorectal cancer significantly reduces the number of subjective clinical manifestations (positional tests) in the main group – 17%, and in the control group – 54.3%, as well as objective clinical manifestations (instrumental research methods) in Group I – 13%, and Group II – 89.5%, respectively. The study shows that in re-operated patients with colorectal cancer who received 5-fluorouracil, abdominal adhesions are characterized by a low content of collagen and fibroblasts, low vascularization and a high content of polymerized fibrin strands. It was also found that re-operated patients with colorectal cancer who did not receive 5-fluorouracil, abdominal adhesions are characterized by a high collagen content, a large number of fibroblasts, and severe angiogenesis. Conclusion: It was found that the prolonged administration of 5-fluorouracil statistically significantly reduces the risk of adhesions, thereby showing the effectiveness of preventing adhesive disease of the abdominal organs. It was shown that the prolonged administration of 5-fluorouracil significantly reduces the number of subjective and objective signs of adhesive disease of the abdominal organs, as well as significantly decreases intraoperative and postoperative complications, the duration of the operation, and the amount of blood loss. In the postoperative period, it reduces the length of hospital stay and improves the quality of life of patients.