Evaluating the completeness of postoperative endoscopic recurrence assessment in Crohn's disease patients with Kono-S...

Despite therapeutic advances, resection rates in Crohn's disease remain high. Kono-S is a novel anastomosis for ileocolonic resections; however, its altered configuration may challenge standard endoscopic assessment, particularly in the absence of validated scoring tools. This study evaluated the endoscopic assessment of Kono-S anastomosis anatomy and recurrence stratification using Rutgeert's score.

This retrospective study included colonoscopies performed on Crohn's disease patients with Kono-S anastomosis between March 2021 and 2025. Data included procedure dates, endoscopist subspecialty [inflammatory bowel disease (IBD) vs. non-IBD], and colonoscopy findings. Colonoscopies were rescored via Rutgeert's score and evaluated for completeness of assessment, defined as correct identification and photodocumentation of the anastomosis substructures. Factors associated with completeness were determined using Mann-Whitney U or Fisher's exact tests. Inter-rater reliability between endoscopists was calculated using Fleiss' kappa.

Forty-nine colonoscopies performed a median of 31 weeks postsurgery were included. Endoscopic recurrence (≥i2b) was 16.2% (median follow-up 153 weeks). Most procedures (89.5%) were performed by IBD subspecialists. Thorough assessments were achieved in 73.5% of colonoscopies, with IBD endoscopists significantly more likely to provide complete assessments (79.5%) compared with non-IBD endoscopists (20%, P  = 0.014). Agreement with the rescored Rutgeerts occurred in 41 (93.2%) cases. Concordance with the central reading was high for IBD endoscopists (Fleiss' kappa: 0.897, P  < 0.001) but tended towards moderate for non-IBD endoscopists (Fleiss' kappa: 0.467, P  = 0.351).

With increasing adoption of the Kono-S technique, this study suggests that IBD-specific endoscopy training is essential for accurate assessment of postoperative recurrence in patients with Crohn's disease.