In inflammatory bowel disease (IBD) surveillance, current ESGE guidelines recommend a minimum neoplasia detection rate of >8%, whilst desirable detection rates have not been defined.¹ These recommendations, however, are based on a limited number of studies, predominantly carried out in academic referral centres. We therefore aimed to evaluate neoplasia detection rates in IBD surveillance at a nationwide level, assessing performance across all endoscopists to determine whether existing detection rate thresholds should potentially be adjusted. Furthermore, to assess if conventional adenoma detection rate (ADR) in colorectal cancer screening correlates with neoplasia detection rate in IBD surveillance. 

We utilized data from the Swedish Registry for Colorectal Cancer Screening and Colonoscopy (SveReKKS), a prospectively entered, web-based national register. Data were retrieved for the period April 2019 to October 2025. Variables extracted from the registry included indication for colonoscopy, bowel preparation, ileocecal intubation, presence of suspected malignancy, polyp detection, biopsy or removal of polyp, and corresponding histopathological results. Neoplasia detection was defined as dysplasia in lesions that were removed or biopsied. Data were not available for lesions that were not classified as polyps or cancer in the registry, nor for cases of “invisible” dysplasia (i.e., dysplasia in random biopsies). Adequate bowel preparation was defined as Boston Bowel Preparation Scale score >6 in total, with an individual segment score of ≥2. 

In total, 8,757 IBD surveillance colonoscopies were performed by 333 endoscopists. After excluding endoscopists that had registered less than 50 IBD surveillance colonoscopies, 3,386 endoscopies and 40 endoscopists remained. The mean age of the patients in the cohort was 53 (SD 15) years and the proportion of males was 58%. Bowel preparation was adequate in 95% of colonoscopies and ileocecal intubation was achieved in 97%. The overall neoplasia detection rate was 8.8% (95% CI 7.9, 9.8%), and cancer detection rate was 0.15% (95% CI 0.05, 0.34%). Endoscopist-specific detection rates ranged from 0.8% to 21.8%. The second-highest quintile (60–80%) and highest quintile (80–100%) of endoscopists had detection rates of 9.6–13.0% and 13.2–21.8%, respectively. Overall, 22 endoscopists registered more than 50 colonoscopies for both colorectal cancer screening and IBD surveillance. Among these endoscopists, adenoma detection rate (ADR) and neoplasia detection rate demonstrated a moderate-to-strong correlation (R² = 0.59; β = 0.37 [95% CI 0.23–0.52]). However, among endoscopists with a neoplasia detection rate <8%, ADR still ranged widely from 32% to 58%.

These results indicate that the current European guidelines for neoplasia detection in IBD surveillance seem reasonable, however, higher detection rates can be achieved. Therefore, raising the minimum neoplasia detection threshold in IBD surveillance, and setting desirable thresholds, can be considered. Furthermore, although a high ADR in colorectal cancer screening correlated with neoplasia detection, this correlation was not absolute, suggesting that deidicated training in neoplasia detection in IBD surveillance may be required.