S1457 Diagnostic Accuracy of Bowel Ultrasonography in Monitoring Inflammatory Bowel Disease: An Updated Systematic Review and Meta-Analysis

Introduction: Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), requires regular monitoring to guide treatment. While colonoscopy is the gold standard, its invasiveness limits its routine use. Bowel ultrasonography (BUS) has emerged as a noninvasive, accessible imaging tool for IBD. The objective of this study was to evaluate the diagnostic accuracy of BUS in detecting IBD activity compared to colonoscopy, with detailed assessment of sensitivity, specificity, and performance across BUS modalities. Methods: A systematic review and meta-analysis included 37 studies assessing BUS modalities—standard BUS, color Doppler, small intestine contrast ultrasonography (SICUS), and contrast-enhanced ultrasound (CEUS). Pooled sensitivity, specificity, diagnostic odds ratios (DOR), and likelihood ratios were calculated, with subgroup analyses by modality and IBD subtype. Results: The overall pooled sensitivity and specificity of BUS for IBD were 90.0% and 83.5%, respectively. Among modalities, SICUS demonstrated the highest sensitivity (95.0%), while BUS with color Doppler showed the highest specificity (85.1%). CEUS achieved the strongest diagnostic power, with a DOR of 75.52. Condition-specific analyses revealed that BUS was most effective for detecting postoperative CD recurrence (sensitivity 91.9%, DOR 61.9), with CD evaluations showing the lowest false-positive (13.9%) and false-negative (8.1%) rates. Meta-regression identified side-to-side anastomosis as a significant predictor of improved diagnostic performance (P = 0.003). Across all subgroups, BUS consistently showed robust positive and negative likelihood ratios, supporting its use as a reliable noninvasive diagnostic tool. Conclusion: BUS offers high diagnostic accuracy for IBD, particularly postoperative CD, with modality-specific strengths: SICUS excels for screening, color Doppler BUS for confirmation, and CEUS for overall diagnostic power. Future research should focus on protocol standardization, head-to-head comparisons with magnetic resonance and computed tomography enterography, and evaluating BUS’s integration into long-term IBD management.