Why is FIT important for people with lower gastrointestinal symptoms?

If you consult your doctor about bowel symptoms, they may speak about getting FIT. What is FIT? In this context, it is nothing to do with exercise or how far you can run. FIT stands for faecal immunochemical test, which aims to detect blood in your faeces. The test is highly sensitive.

People with lower bowel symptoms such as a change in their bowel habits will understandably be concerned about the possibility of bowel cancer. The risk of colorectal cancer in people with a negative FIT, a normal examination and normal full blood count is <0.1%. This is lower than the general population risk of colorectal cancer. So this combination of clinical findings allows your doctor to conclude that you are very unlikely to have bowel cancer. However, many people with lower GI symptoms still do not undergo FIT before referral to a specialist.

Patients with a FIT of fHb <10μg Hb/g, a normal full blood count, and no ongoing clinical concerns do not need to be referred on a lower GI urgent cancer pathway but can be managed in primary care or referred on an alternative pathway with suitable safety netting if symptoms change. FIT can improve patient management. By fully implementing the use of FIT in people with lower GI symptoms in primary care, we can spare patients unnecessary colonoscopies, releasing capacity to ensure the most urgent symptomatic patients are seen more quickly in specialist clinics.

There are some patients for whom FIT is not suitable, such as those with iron deficiency anaemia, a rectal or anal mass, or anal ulceration. See below for further guidance on the use of FIT in people with lower GI symptoms.

https://www.england.nhs.uk/wp-content/uploads/2022/10/B2005_i_Using-faecal-immunochemical-testing-lower-gastrointestinal-pathway_primary-care-letter.pdf

https://www.bsg.org.uk/clinical-resource/faecal-immunochemical-testing-fit-in-patients-with-signs-or-symptoms-of-suspected-colorectal-cancer-crc-a-joint-guideline-from-the-acpgbi-and-the-bsg/