Small bowel diseases pose a unique diagnostic and management challenge and often requires tertiary specialist referral. The use of biomarkers may provide a cheap, noninvasive tool to assess the small bowel in terms of diagnosis, offering a better way to triage referrals and select patients for early management. This review looks at the most recent evidence behind the use of several faecal and urine biomarkers for small bowel diseases.Faecal calprotectin shows the most promise, with evidence to support its role in predicting relapse postsurgery and monitoring treatment response in patients with Crohn's disease. A faecal calprotectin less than 50 μg/g may also be used as a cut-off to triage further investigation. Faecal lactoferrin also appears promising as a marker of small bowel inflammation. A positive faecal immunohistochemistry test precapsule may help to prioritize referrals for obscure bleeding.The use of biomarkers in the diagnosis and management of small bowel disease is still controversial and remains unclear. More studies are required to further develop their potential and before societal guidelines can be developed to direct their appropriate use in clinical practice.
M S Ismail, Serhiy Semenov, Deirdre McNamara