From obstruction to ischaemia: a systematic review and meta-analysis on the diagnostic accuracy of CT scans in identifying small and large bowel obstruction, underlying causes and predicting critical complications in adults.

Objectives To evaluate the diagnostic accuracy of CT in identifying small and large bowel obstruction and associated complications, including ischaemia and perforation, in adult patients. Design Systematic review and meta-analysis reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy reporting guidelines. Data Sources Ovid MEDLINE and Embase were searched from 1946 to 20 February 2025. Eligibility Criteria The study included randomised controlled trials, cohort studies and case-control studies evaluating the diagnostic accuracy of CT for bowel obstruction in adults (aged ≥18 years). Only studies published in English were included. Conversely, case reports, editorials, conference abstracts without full data and studies focusing exclusively on paediatric populations or animal models were excluded. Data Extraction And Synthesis Three reviewers independently extracted data on study characteristics, CT modality, diagnostic accuracy metrics (sensitivity, specificity and predictive values) and complications. Risk of bias was assessed using the QUADAS-2 tool. A random-effects meta-analysis was conducted. Heterogeneity was assessed using I² and Tau² statistics. Results Sixty-five studies with 9418 patients were included. The pooled sensitivity and specificity of CT for bowel obstruction were 90% (95% CI 78 to 96; I²=56%, Tau²=0.36) and 88.8% (95% CI 78.0 to 94.8; I²=65%, Tau²=0.35), respectively. For bowel ischaemia, CT showed a pooled sensitivity of 47.0% (95% CI 32.4 to 59.9; I²=0%, Tau²=0.00) and specificity of 85.3% (95% CI 77.9 to 89.5; I²=1%, Tau²=0.45). Multidetector CT (MDCT) outperformed older modalities across all endpoints. Ischaemia was present in 22.05% of all cases, with higher rates in small bowel obstruction. Perforation and mortality rates were 3.98% and 4.40%, respectively. No significant publication bias was detected, and the certainty of evidence was graded as moderate for most diagnostic accuracy outcomes. Conclusions CT, particularly MDCT, offers high diagnostic accuracy for bowel obstruction and is a critical tool for detecting serious complications such as ischaemia and perforation. However, sensitivity for ischaemia remains modest. Standardised protocols and prospective studies are needed to enhance early identification and optimise care pathways.