Understanding Faecal Immunochemical Testing (FIT) and its role in bowel cancer detection

Early detection of bowel cancer is crucial for effective treatment and improving survival rates. One of the key tools in this process is Faecal Immunochemical Testing (FIT).
In this article, we spoke to leading consultant colorectal surgeon, Mr Michael Machesney to explain what FIT is, why it is important, and how it compares to other screening methods for bowel cancer.

What is Faecal Immunochemical Testing (FIT)?

Faecal Immunochemical Testing (FIT) is a non-invasive screening method used to detect hidden blood in the stool, which can be an early sign of bowel cancer.

Unlike previous stool tests, FIT specifically targets human haemoglobin (the protein in blood), making it more accurate and easier for patients to complete.
The test involves collecting a small stool sample at home using a provided kit, which is then sent to a laboratory for analysis.

Why is FIT important in the early detection of bowel cancer?

FIT plays a crucial role in the early detection of bowel cancer. Bowel cancer often develops slowly, and early stages may not present noticeable symptoms. By detecting tiny amounts of blood in the stool, FIT can identify potential cancers before they cause symptoms, when they are more likely to be treatable.

This early detection significantly improves the chances of successful treatment and can reduce the need for more aggressive interventions.

How does FIT compare to other screening methods for bowel cancer?

FIT is an excellent screening tool, especially when compared to other methods like colonoscopy or sigmoidoscopy. One of the main advantages of FIT is its convenience—patients can complete the test at home without any preparation or discomfort.

While a colonoscopy is the gold standard for bowel cancer detection, it is more invasive, requires bowel preparation, and involves some risks. FIT, on the other hand, is less invasive, more accessible, and can be repeated more frequently, making it a practical option for routine screening. However, it is important to note that FIT is primarily a screening tool.

If FIT results are positive, a colonoscopy is usually recommended to further investigate the cause of the bleeding.

What does a positive FIT result mean?

A positive FIT result indicates that blood has been detected in the stool.

This does not necessarily mean that the individual has bowel cancer, as blood in the stool can result from various conditions, including haemorrhoids, diverticular disease, or inflammatory bowel disease. However, a positive result should never be ignored. It requires further investigation, typically through a colonoscopy, to determine the source of the bleeding and rule out or confirm the presence of cancer.

Can a negative FIT result completely rule out bowel cancer?

While a negative FIT result is reassuring, it does not entirely rule out the possibility of bowel cancer.

FIT is highly effective at detecting cancers that are actively bleeding, but it may miss cancers or polyps that are not bleeding at the time of the test. Therefore, if a person has symptoms suggestive of bowel cancer, such as persistent changes in bowel habits, unexplained weight loss, or abdominal pain, they should seek medical advice even if their FIT result is negative.

In conclusion, FIT is a powerful tool in the early detection of bowel cancer, offering a non-invasive and accessible method for screening. While it has its limitations, its role in detecting hidden blood in the stool makes it an invaluable component of bowel cancer prevention strategies.

If you are eligible for screening, you should be encouraged to take advantage of the FIT test and consult a consultant colorectal surgeon for further guidance based on your results. Early detection could make all the difference in your treatment and recovery.