Factors Associated with Anastomotic Leak After Colostomy Reversal in Northwest Ethiopia: A Retrospective Case–Control Study

Abstract Anastomotic leak is a feared complication after gastrointestinal surgery; however, the risk factors following colostomy reversal in low-resource settings remain poorly defined. We conducted an institution-based case–control study at Debre Markos Comprehensive Specialized Hospital, northwest Ethiopia, using data from all patients who underwent colostomy reversal between 1 January 2016 and 31 December 2024. Cases were patients with a documented anastomotic leak during the index hospitalization or within 30 days postoperatively, while controls had no anastomotic leak. Data were extracted using a pretested checklist and analyzed using binary logistic regression. Of 225 eligible patients, 56 (24.9%) developed an anastomotic leak. Factors independently associated with anastomotic leak were residence more than 60 km from the hospital (adjusted odds ratio [AOR] = 8.45, 95% confidence interval [CI]: 3.43–20.83), colostomy duration of less than 3 months (AOR = 2.53, 95% CI: 1.10–5.82), comorbid illness (AOR = 5.15, 95% CI: 1.97–13.49), significant intraoperative adhesions (AOR = 2.73, 95% CI: 1.15–6.49), a short distal stump (AOR = 2.82, 95% CI: 1.18–6.74), iatrogenic bowel injury (AOR = 3.20, 95% CI: 1.09–9.46), failure to pass flatus within 72 hours (AOR = 5.84, 95% CI: 1.63–20.91), and other postoperative complications (AOR = 3.48, 95% CI: 1.03–11.73). Anastomotic leak after colostomy reversal is influenced by patient-related, geographic, intraoperative, and postoperative factors, several of which are modifiable. Preoperative optimization, appropriate timing of reversal, meticulous adhesiolysis, avoidance of bowel injury, careful assessment of the distal stump, and vigilant postoperative monitoring may reduce leak-related morbidity and mortality in similar resource-constrained settings.