Get FIT for the new year: a review of the role of faecal immunochemical test for haemoglobin in patients with symptoms of colorectal disease

Colorectal cancer (CRC) incidence is high and whilst the role of colonoscopy in diagnosing CRC in symptomatic individuals is undisputed, there is a need for reliable rule-out criteria to alleviate the burden on the colonoscopy service. Overlap of symptoms that it is often difficult to filter significant colorectal disease from non-significant disease; hence clinical examination needs to be supplemented by further investigation. Biomarkers for CRC have been evaluated in the literature and the faecal immunochemical test for haemoglobin (FIT) is a promising a simple, inexpensive and reproducible tool in both the primary and the secondary care setting. Whilst the value of FIT in CRC screening has been long-established, more recent work has focused on its role in the patient presenting with symptoms of colorectal disease. Negative predictive value of FIT for CRC in patients presenting with symptoms has been shown in the literature to be 100%, with FIT-positive subjects carrying as high as a 60% probability of having CRC. When utilised in a clinical context, and with implementation of safety-netting, FIT is a robust and reliable tool in the patient who presents with symptoms of colorectal disease. FIT-negative, symptomatic patients are unlikely to have significant colonic disease and persisting symptoms should be investigated with cross-sectional imaging instead of colonoscopy.