Future methods for the diagnosis of inflammatory bowel disease

The diagnosis of inflammatory bowel disease (IBD) remains a challenge for clinicians, and patients. Clinical suspicion of these disorders leads to a diagnostic pathway that may include stool testing, colonoscopy, radiological tests and capsule examinations. This workup is unpleasant, embarrassing, painful and occasionally dangerous. Alternative means of diagnosing IBD are being explored. Genetic testing and serology have not been found to be sufficiently specific or sensitive to be used for diagnosis. Faecal markers, however, have demonstrated some potential. Faecal lactoferrin and calprotectin may be used to differentiate IBD from non-inflammatory disorders and these tests are now commonly used, with support from the National Institute for Health and Care Excellence. Recent research has focused upon volatile organic compounds emitted from bodily fluids, including faeces, urine and breath. Headspace gas from faeces or urine may be analysed by gas chromatography/mass spectrometry. Models have been built based on these compounds to enable Crohn's disease and ulcerative colitis to be distinguished from irritable bowel syndrome (IBS) and from healthy controls. Similar work has found that headspace gases from urine may be used to diagnose IBS. Faecal samples are relatively easy to obtain, but patients dislike collecting samples, so a urinary test is an attractive alternative. Early data from breath samples also show potential and will be presented. Non-invasive diagnosis of IBD is becoming a reality that will save patients from discomfort, embarrassment and risk, and may mean significant savings for healthcare providers.