Objective: 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.

Conclusions: 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.