Faecal haemoglobin concentration measurement: an essential examination

Abstract

Guaiac-based faecal occult blood tests (gFOBT) have some limited applications in colorectal cancer screening programmes, but are not recommended for assessment of patients with lower abdominal symptoms and are badly used in clinical practice. Faecal immunochemical tests for haemoglobin (FIT) are replacing gFOBT in screening programmes because they have many advantages, including that faecal haemoglobin concentration can be quantitated using automated immunoturbidimetry. In countries with limited colonoscopy resources, the services are now becoming overwhelmed with referrals from primary care as well as from screening and surveillance programmes. Options to deal with this include reinforcing current objective-based guidelines, expanding colonoscopy resources, or using simple faecal tests to assess patients presenting with suspected colorectal disease. There are many data on use of FIT in screening for detection of colorectal cancer and advanced adenoma: newer data on the use of FIT in primary care show that, although faecal haemoglobin is not a good diagnostic rule-in test for colorectal disease, it has very high negative predictive value, making it a very good rule-out test. Along with use in surveillance programmes, this application of faecal haemoglobin assays would improve use of colonoscopy services and facilitate patient care. Faecal haemoglobin analyses should become an essential examination.