© 2016 Elsevier Inc. Background Postoperative ileus is a common cause of increased morbidity and cost after operative intervention. The aim of this study was to assess how fluid type, volume, and timing may affect incidence of postoperative ileus. Methods A retrospective cohort study was performed on patients undergoing operative intervention for rectal cancer from 2008 to 2015 at a single institution. Univariate and multivariate analyses were used to assess the effect of type (crystalloid versus colloid), volume by quartile, and timing (perioperative versus postoperative) on rate of postoperative ileus. Results A total of 300 patients were included, and the overall incidence of ileus in our cohort was 30% (n = 90). Both univariate and multivariate analyses showed that increasing volume of crystalloid volume administered was associated with increased postoperative ileus incidence (first quartile: 16.3%; second quartile: 31.5%, third quartile: 34.2%; and fourth quartile: 39.2%; P = .012), and administration of colloid was not shown to correlate. Furthermore, timing was not shown to be associated with the rate of postoperative ileus. Conclusion Increased volumes of crystalloid are associated with higher rates of ileus, while administration of colloid is not. Based on this retrospective data, limiting the volume of crystalloid perioperatively may help lower the rate of ileus postoperatively.