The potential of volatile organic compounds for the detection of active disease in patients with ulcerative colitis

Summary Background To optimise treatment of ulcerative colitis (UC), patients need repeated assessment of mucosal inflammation. Current non‐invasive biomarkers and clinical activity indices do not accurately reflect disease activity in all patients and cannot discriminate UC from non‐UC colitis. Volatile organic compounds (VOCs) in exhaled air could be predictive of active disease or remission in Crohn's disease. Aim To investigate whether VOCs are able to differentiate between active UC, UC in remission and non‐UC colitis. Methods UC patients participated in a 1‐year study. Clinical activity index, blood, faecal and breath samples were collected at each out‐patient visit. Patients with clear defined active faecal calprotectin >250 μg/g and inactive disease (Simple Clinical Colitis Activity Index