S1679 Real-World Comparative Outcomes of Intestinal Ultrasound vs Fecal Calprotectin for Monitoring Inflammatory Bowel Disease

Introduction: Monitoring inflammatory bowel disease (IBD) activity is crucial for guiding treatment decisions. While fecal calprotectin (FCAL) is a widely used non-invasive biomarker, intestinal ultrasound (IUS) has emerged as a rapid, radiation-free imaging modality capable of directly visualizing bowel inflammation. This study compared real-world outcomes in IBD patients monitored using IUS vs FCAL. Methods: We queried the TriNetX US Collaborative Network to identify adult patients (≥18 years) with Crohn’s disease or ulcerative colitis who underwent either IUS or FCAL. Patients were excluded if they received both tests within the same period. Propensity score matching (1:1) was performed based on demographics, comorbidities, and baseline medication use. Outcomes assessed within one year of testing included corticosteroid use, biologic therapy escalation, IBD flares, surgery, fistula, obstruction, and repeat endoscopy. Risk ratios, odds ratios, and Kaplan-Meier analyses were conducted. Results: After matching, 818 patients were included in each cohort. Compared to the FCAL group, the IUS group had significantly lower rates of biologic escalation (HR 0.316; 95% CI: 0.234–0.427; P < 0.001) and IBD flares (HR 0.188; 95% CI: 0.125–0.283; P < 0.001). No statistically significant differences were observed in corticosteroid use, surgery, fistula, obstruction, or repeat endoscopy. Conclusion: Use of IUS for IBD monitoring was associated with significantly fewer flares and reduced need for biologic escalation compared to FCAL. These improved outcomes may be attributed to the advantages of IUS; particularly its ability to provide direct visualization of bowel inflammation and immediate, real-time feedback, enabling more timely and targeted clinical decision-making. These findings support broader integration of IUS into routine IBD management pathways.