P85 Faecal volatile organic compounds in paediatric inflammatory bowel disease

Faecal volatile organic compounds (VOCs) result from the metabolism of the intestinal mucosa, gut microbiota and the environment. Faecal VOCs may provide novel insights into the pathogenesis of gastrointestinal disorders. Method We assessed faecal VOCs by gas chromatography-mass spectrometry in a prospective, observational study of children with suspected inflammatory bowel disease (IBD) attending 3 specialist clinics. We tested whether the abundance of faecal VOCs differed according to IBD versus other gastrointestinal disorders, IBD subtype and response to treatment in IBD. Results We characterised faecal VOCs in 132 children in whom IBD was diagnosed and 132 non-IBD controls. 162 (61.4%) were boys. Mean age was 12.2 years (SD 3.0). In total 214 (81.1%) were white, 35 (13.3%) were Asian and 15 (5.7%) of other ethnic background. There were 78 (29.5%) children with Crohn’s disease (CD), 38 (14.4%) with ulcerative colitis (UC) and 16 (6.1%) IBD-unclassified. The most common diagnosis in controls was a functional gastrointestinal disorder. The abundance of 18/30 (60.0%) faecal VOCs differed significantly between IBD and controls (t-test; p Within IBD, the subtype (CD versus colitis (UC and IBD-unclassified)) described a small amount of variation (3%, p=0.006), with three faecal VOCs (6-methylhept-5-en-2-one; benzaldehyde; 4-methylphenol) significantly different in abundance between CD and colitis (t-test, p Conclusion/Interpretation Characterisation of faecal VOCs may advance the understanding of the pathogenesis of IBD, disease sub-types and response to treatment.