Routine versus postoperative CRP/CT guided selective diverting ileostomy after laparoscopic low anterior resection for rectal cancer: a comparative randomized controlled trial

BACKGROUND: Diverting ileostomy is routinely used to protect the anastomosis after laparoscopic low anterior resection (LAR) for rectal cancer, but it exposes most patients to stoma-related morbidity even though only a minority develop a true anastomotic leak. This trial evaluated whether a postoperative C-reactive protein (CRP) and computed tomography (CT) guided selective ileostomy strategy could reduce the rate of ileostomy formation compared with routine diversion. METHODS: In this RCT, 200 patients with stage II or III middle or lower third rectal cancer undergoing laparoscopic LAR were randomized 1:1 to a CRP/CT-guided selective ileostomy group (n = 100) or a routine diverting ileostomy group (n = 100). In the CRP/CT group, serum CRP was measured daily from postoperative day 1; a threshold of 114 mg/L on day 3 or a rise greater than 15 mg/L per day triggered confirmatory contrast-enhanced CT, with ileostomy formed only if findings were suspicious for leak. The primary outcome was the stoma-free status throughout the 12-month follow-up. RESULTS: Baseline demographic and tumor characteristics were similar between groups (all p > 0.05). Ileostomy formation was markedly lower in the CRP/CT group than the routine group (22.0% vs. 100.0%, p < 0.001). Anastomotic leak rates did not differ (0% vs. 1.0%, p = 1.000), nor did overall complication rates (31.0% vs. 32.0%, p = 0.879). Operative time (148.4 ± 14.0 vs. 166.6 ± 13.1 min, p < 0.001) and intraoperative blood loss (168.9 ± 28.2 vs. 197.3 ± 39.7 mL, p < 0.001) were significantly lower in the CRP/CT group. Stoma-related complications were far less frequent with the selective strategy (3.0% vs. 30.0%, p < 0.001). The CRP/CT group reported significantly better global health status, physical functioning, and emotional functioning scores (all p < 0.001). CONCLUSION: A postoperative CRP/CT-guided selective ileostomy strategy reduces the need for diverting ileostomy after laparoscopic low anterior resection for rectal cancer while improving operative outcomes and quality of life; however, confirmed leakage was infrequent in both groups. This approach may serve as an alternative to routine diversion in appropriately monitored surgical units. TRIAL REGISTRATION: This trial was retrospectively registered at ClinicalTrials.gov (Identifier: NCT07722533) on July 17, 2026.