AIM: This study aims to investigate the effects of pure olive oil on mucosal atrophy of the distal colon in rats. <br/><br/>Material and methods: The study included 28 male albino Wistar rats weighing 300-350 g. A total of 28 animals were randomly allocated to four groups: group 1: control group (n = 6); group 2: ostomy group (n = 6); group 3: ostomy + saline group (n = 8); group 4: ostomy + olive oil group (n = 8). By definition, group 1 did not undergo any procedure. The same surgical procedure was performed for groups 2, 3, and 4 as described below. In all animals from these groups, a two-centimeter-long mid-line incision was made and the colon was divided into 5 cm sections, measured from the distal colon to the caecum. Proximal and distal stomas were created 2 cm apart in the midline with the use of single-layer interrupted sutures. All rats were kept under close daily observation until they were terminated postoperatively after the 1st month. Animals from group 2 did not undergo any additional procedures, while those fromgroups 3 and 4 were given 2 mL of saline and olive oil twice a day, respectively. At the end of the 1st month, the rats were re-operated through the same approach. Biopsies were taken from the proximal and distal stomas of all rats in the same manner for further histopathological analysis. <br/><br/>Results: Group 1 showed no significant differences in terms of mucosal thickness, muscular thickness, wall thickness or colonic lumen diameter between the proximal and distal segments of the colon. Although there were significant differences between the proximal and distal colostomies for each parameter in groups 2, 3, and 4, the mucosal thickness, muscular thickness, wall thickness, and colonic lumen diameter differences for proximal and distal ostomies were very small in group 4 when compared to groups 2 and 3. <br/><br/>Conclusion: The administration of pure olive oil through the distal colon before colostomy closure may reduce the difference in diameter between the proximal and distal intestinal segments. As a result, a more straightforward surgical procedure may be achieved.