Abstract

Background
Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), necessitates frequent disease monitoring to guide management. While colonoscopy remains the gold standard for assessing disease activity, its invasive nature limits its feasibility. Bowel ultrasonography (BUS) has emerged as a noninvasive alternative.

Objective
This systematic review and meta‐analysis evaluate the diagnostic accuracy of BUS in detecting IBD activity compared to colonoscopy.

Methods
A comprehensive literature search of PubMed, CINAHL and Embase was conducted, including 37 studies evaluating BUS modalities such as colour Doppler, small intestine contrast ultrasonography (SICUS) and contrast‐enhanced ultrasound (CEUS). Pooled sensitivity, specificity, diagnostic odds ratios (DOR) and likelihood ratios were calculated. Subgroup analyses were performed based on diagnostic modality and IBD subtype.

Results
The overall pooled sensitivity and specificity of BUS in IBD were 90.0% and 83.5%, respectively. SICUS had the highest sensitivity (95.0%), while BUS with colour Doppler had the highest specificity (85.1%). CEUS demonstrated the highest DOR (75.52). BUS performed best in detecting postoperative CD recurrence (sensitivity 91.9%, DOR 61.9). Meta‐regression identified surgical anastomosis type as a significant predictor of diagnostic performance.

Conclusion
BUS is a highly effective noninvasive imaging modality for diagnosing and monitoring IBD. Its accuracy varies by modality, with SICUS optimal for screening and colour Doppler BUS for confirmation. Future studies should standardize BUS protocols and evaluate its role alongside MRI and CT enterography.