Capsule endoscopy: High negative predictive value in the long term despite a low diagnostic yield in patients with suspected Crohn's disease

Introduction: The role of small bowel capsule endoscopy (SBCE) in Crohn's disease (CD) has expanded with greater understanding of the technology. The ability of SBCE to differentiate CD from other causes of inflammation has been questioned. Longitudinal studies are required to assess the long-term impact and significance of SBCE findings in suspected CD. This study aimed to determine the long-term clinical accuracy of SBCE in patients referred with suspected CD. Methods: A retrospective review was carried out on SBCE procedures performed for suspected CD since 2010. Only patients with at least 6 months of documented follow up were included. A chart review was undertaken to record SBCE findings/correlate with subsequent diagnosis and outcome. Results: In all, 95 patients with sufficient follow up were identified. The mean follow up was 13 months (range 8-24). In total, 72 (76%) SBCEs were negative and 23 (24%) positive for CD. Of the 72 negative tests, two patients (3%) were later diagnosed with CD. The negative predictive value is 96%. There was a strong positive correlation between results of WCE and subsequent clinical diagnosis. Conclusions: SBCE appears capable of safely out-ruling CD, with only 3% of negative SBCE investigations being diagnosed with CD after 15 months.