Postoperative Ileus After Rectal Cancer Surgery: Assessing Incidence, Severity, and Impact Across Open, Laparoscopic, and Robotic Approaches

<b>Background/Objectives:</b> Postoperative paralytic ileus (POI) is a common complication after rectal resections. Although it is often argued that laparoscopic or robotic surgery reduces ileus compared to open surgery, research indicates that the incidence rates remain considerably high after minimally invasive surgery (MIS), and it is unclear whether laparoscopy or robotic surgery confers lower ileus rates. Furthermore, the literature lacks consistency in defining ileus and does not adequately address the severity levels of this complication. This study aims to compare the incidence and severity of ileus after open, laparoscopic, and robotic oncologic rectal resections, using definitions established in the current literature. <b>Methods:</b> This is a retrospective cohort study including patients who underwent rectal resection in a single tertiary academic-affiliated hospital between the years 2014 and 2019. The study compared patients who underwent laparoscopic and robotic surgeries to those who underwent open surgery. <b>Results:</b> The study involved 337 patients who underwent oncologic rectal resection. Among them, 188 underwent laparoscopic, 59 robotic and 90 underwent open surgery. The overall incidence of postoperative paralytic ileus (POI) was 19.6%, with a significant difference observed between surgical approaches: 15.4% in the MIS group compared to 31.1% in the open surgery group (<i>p</i> < 0.001). Additionally, a lower ileus incidence was noted between the robotic (8.5%) and laparoscopic (17.6%) subgroups, but it did not reach statistical significance (<i>p</i> = 0.092). The severity of ileus did not differ significantly between laparoscopic, robotic and open surgery. Ileus risk factors that were found included advanced age, male gender, high ASA score, preoperative anemia, intraoperative bowel injury, and postoperative opioid use. <b>Conclusions:</b> MIS for rectal cancer is linked to a significantly lower rate of POI compared to open surgery. However, when ileus does occur, its severity is comparable across all techniques.