Oral vancomycin solution is superior to capsule in inducing clinical biomarker and endoscopic remission in children with atypical ulcerative colitis

Aims Atypical colitis (presenting reverse gradient colitis, backwash ileitis or rectal sparing) is associated with primary sclerosing cholangitis–ulcerative colitis (PSC). Oral vancomycin has been used to manage paediatric atypical colitis with/without confirmed PSC. Different preparations had shown different efficacy. We compared oral vancomycin solution to capsules in inducing remission in children with atypical colitis, while assessing other potential confounders. Methods Children using oral vancomycin for at least 3 months to manage atypical colitis were retrospectively identified. Factors associated with colitis remission (Paediatric Ulcerative Colitis Activity Index [PUCAI], faecal calprotectin, colonoscopy and histology) were explored. Results Of 32/48 children with elevated PUCAI, 27/32 achieved PUCAI < 10 (20/23 after solution vs . 7/9 after capsules, P = .520). Faecal calprotectin <100 μg/g was achieved in 35/48 (28/35 after solution vs . 6/13 after capsules, P = .022). Follow‐up colonoscopy during treatment ( n = 25) showed reduced Mayo from median 2 to 0 ( P < .001) after solution vs . from 2 to 1 ( P = .257) after capsules. Pan‐colonic histological remission was seen in 14/25 (12/20 after solution vs . 1/5 after capsules, P = .109). In adjusted analysis, use of oral vancomycin solution was a significant predictor for biomarker (adjusted odds ratio 23.1, 95% confidence interval 2.11–253) and pan‐colonic histological remission (adjusted odds ratio 900, 95% confidence interval 1.61–504 929). No other predictors were identified. Within 12 months after ceasing oral vancomycin in children who achieved remission, 52% relapsed. No clinical predictors, including vancomycin preparation, were established. Conclusion Oral vancomycin solution was superior to capsules for inducing biomarker and colonoscopic remission in children with atypical colitis with/without confirmed PSC. This finding warrants further investigation to ensure optimal use.