Association of Intraoperative Fluid Exposure with Time to First Flatus after Laparoscopic Radical Resection for Colorectal Cancer: A Retrospective Cohort Study

Background Intraoperative fluid exposure may influence early bowel recovery after laparoscopic colorectal cancer surgery.Methods This retrospective cohort study included adults who underwent laparoscopic radical resection for colorectal cancer at a single tertiary center between January 2021 and September 2025. Total intraoperative fluid input and estimated net fluid balance (input minus urine output and blood loss) were analyzed per 500 mL increase. The primary outcome was time to first flatus; secondary outcomes were delayed flatus (≥3 days), time to first defecation, and postoperative length of stay.Results Among 203 patients, 47 (23.2%) had delayed flatus. Higher total input was associated with longer time to first flatus (aIRR 1.046, 95% CI 1.005–1.089; p = 0.027), as was estimated net balance (aIRR 1.044, 95% CI 1.005–1.085; p = 0.026). Associations with delayed flatus, defecation time, and length of stay were not statistically significant in adjusted models.Conclusions Greater intraoperative fluid input and more positive estimated net balance were associated with a modest delay in return of flatus after laparoscopic radical colorectal cancer surgery. These retrospective findings are hypothesis-generating and require prospective validation.