Predictors of Failure of Non-Operative Management in Adults with Adhesive Small Bowel Obstruction; A systematic review

Background: Adhesive small bowel obstruction (ASBO) is a frequent emergency after abdominal surgery. Non-operative management (NOM) resolves many uncomplicated episodes, whereas delayed recognition of failure exposes patients to prolonged obstruction, bowel ischemia, resection, and greater resource use. In this systematic review we analyzed patient, clinical, laboratory, imaging, and early-response predictors of NOM failure in adults with ASBO. Methods: A PRISMA-aligned search framework covered PubMed, Scopus, Web of Science Core Collection, and the Cochrane Library through August 2026. Eligible studies enrolled adults with adhesive or postoperative SBO who received initial conservative treatment and reported subsequent operative intervention or another explicit definition of failure. Predictors were analyzed qualitatively because protocols, thresholds, and statistical models differed. Results: We include sixteen original studies published from 2008 to 2026. Repeated imaging predictors included absent small-bowel feces sign, mesenteric haziness or fluid, free intraperitoneal fluid, high-grade or complete obstruction, transition-point or beak-related signs, and greater bowel dilatation. Older age, guarding, fever, comorbidity burden, prior open operations, elevated lactate, C-reactive protein, creatine phosphokinase, and neutrophil-based indices were significant in selected cohorts. Previous successfully treated ASBO episodes were protective in some datasets. Failure of water-soluble contrast progression and persistent high decompression output provided dynamic information. Conclusion: NOM failure is best anticipated through combined clinical and CT assessment supplemented by laboratory and early-response data rather than reliance on a single admission variable.