Distal Limb Closure Versus Non-Closure During Diverting Loop Ileostomy Following Laparoscopic Anterior Resection: A Prospective Non-Randomized Comparative Cohort Study

<title>Abstract</title> <p>Background The clinical value of mechanically closing the distal limb of a diverting loop ileostomy after laparoscopic anterior resection remains uncertain. Closure may theoretically reduce retrograde passage toward the colorectal anastomosis but may also impair distal decompression and delay postoperative recovery. Methods This prospective non-randomized comparative cohort study included 160 adults undergoing elective laparoscopic anterior or low anterior resection with a diverting loop ileostomy at a tertiary colorectal center between 2021 and 2026. Seventy-seven patients underwent distal limb closure and 83 underwent non-closure. Distal limb management was selected by the operating colorectal surgeon according to routine clinical practice and intraoperative judgment; no random allocation was performed. Primary outcomes were anastomotic leakage and postoperative bowel obstruction. Secondary outcomes were anastomotic stricture, length of stay, time to return of bowel function, and Low Anterior Resection Syndrome (LARS) category. Categorical outcomes with small cell counts were compared using Fisher’s exact test. Results Anastomotic leakage occurred in 1 of 77 patients (1.3%) in the closure group and 4 of 83 patients (4.8%) in the non-closure group (Fisher’s exact p=0.369). Anastomotic stricture occurred in 2 of 77 patients (2.6%) and 3 of 83 patients (3.6%), respectively (p=1.000). Length of stay was longer in the closure group (7.9±1.1 vs 6.2±0.9 days; p&lt;0.001), and return of bowel function was later (57.1±4.8 vs 44.8±5.0 hours; p&lt;0.001). Bowel obstruction was numerically more frequent after closure (approximately 10% vs 5%), but the difference was not statistically significant (p=0.24). LARS severity distributions were comparable (p=0.695). Conclusions Distal limb closure was not associated with statistically significant reductions in anastomotic leakage, anastomotic stricture, bowel obstruction, or LARS severity. Non-closure was associated with shorter hospitalization and earlier return of bowel function. Because this was a single-center, non-randomized comparison, these findings require confirmation in adequately powered multicenter randomized trials.</p>