Why does my doctor want a FIT test?
Why do I need to do a FIT test? Your doctor might give you this test as part of the investigation for your symptoms. The FIT results help your doctor decide whether to refer you urgently for more tests. You might have to do this test if you have symptoms which could be caused by bowel cancer.
Abnormal or Positive Results
An abnormal or positive FIT result means that there was blood in your stool at the time of the test. A colon polyp, a pre-cancerous polyp, or cancer can cause a positive stool test. With a positive test, there is a small chance that you have early-stage colorectal cancer.
The positive predictive value of FIT in this low-risk symptomatic population is 7.0% (95% CI 5.1–9.3%), and the negative predictive value is 99.8% (CI 99.5–99.9%).
Blood can be present in the stool for many reasons, including hemorrhoids, ulcers, anal fissures, diverticular disease, or inflammation. And, like any test, FIT may give an abnormal result even though there is nothing wrong.
The fecal immunochemical test (FIT) is a screening test for colon cancer. It tests for hidden blood in the stool, which can be an early sign of cancer. FIT only detects human blood from the lower intestines.
However, in terms of polyp detection, the comparison is vastly different. Here, the FIT-fecal DNA test proved a detection rate for high-grade dysplasia of 62%, which then fell to 42% for detecting any type of polyp. Comparatively, colonoscopy is 75%–93% sensitive for finding any type of polyp smaller than 6 mm.
Delays to colonoscopy of over 9 mo after positive FIT were significantly associated with higher incidence of CRC and advanced stage of CRC at diagnosis (compared with performing colonoscopy within 1 mo). AOR, adjusted odds ratio; CI, confidence interval; CRC, colorectal cancer; FIT, fecal immunochemical test.
The 3 main symptoms of bowel cancer are blood in the stools (faeces), a change in bowel habit, such as more frequent, looser stools, and abdominal (tummy) pain. However, these symptoms are very common.
Conclusions: In this population-based study, FIT+/CRC− patients were at higher risk for esophageal, stomach, and small intestine cancers than were FIT− patients, suggesting that positive FIT results were associated with these cancers.
False-positive (FP) results of fecal immunochemical tests (FITs) conducted in colorectal cancer (CRC) screening could lead to performing unnecessary colonoscopies. Hemorrhoids are a possible cause of FP FIT results; however, studies on this topic are extremely rare.
Does a FIT test show inflammation?
Quantitative FIT can measure the concentration of hemoglobin in feces by using an antibody that targets human hemoglobin. Fcal estimates the degree of inflammation in the gut based on the amount of infiltrating inflammatory cells, whereas FIT measures the amount of blood hemorrhaging from the intestinal mucosa.
About 10 to 15 per cent of people screened with FIT will have an abnormal result and will require additional testing. This does not mean that a cancer was found - the vast majority of people with an abnormal FIT result will not have cancer. Some people with an abnormal FIT result may have polyps.
What if I get an abnormal result? An abnormal FIT result means that blood was found in the stool sample that you submitted. Abnormal FIT results are common and do NOT mean that you have cancer. On average, 10-15 percent of people screened with FIT will have an abnormal result and will require additional testing.
Both fecal immunochemical test (FIT) and fecal calprotectin (Fcal) results are useful biomarkers for ulcerative colitis (UC).
FIT detects signs of colon and rectal cancer. It can also detect some polyps, which are growths that could become cancer later. HOW? You will get a kit from your provider or in the mail with instructions about how to take a sample of stool.
A new study has found that increasing the sensitivity of the faecal immunochemical test (FIT) can help to identify more cases of bowel cancer, advanced polyps (non-cancerous growths) and Inflammatory Bowel Disease (IBD) in younger people when they attend their GP practice with symptoms.
You may be referred for a FIT test if you; Have unexplained abdominal symptoms. Change in bowel habit lasting longer than 3 weeks. Unexplained weight loss.
How long do I have to wait for my FIT results? It takes 1 to 2 weeks for the results.
52% of faecal immunohistochemistry test (FIT)-positive clients in the Irish National Colorectal Cancer Screening Programme (BowelScreen) have adenomatous polyps identified at colonoscopy in round 1.
Some people will be offered a less urgent investigation of the colon. Most FIT negative people will not need any investigations because their risk of colorectal cancer is low.
When should you not do a FIT test?
Which patients are eligible for FIT? Faecal occult blood tests should not be offered patients, with an abdominal or rectal mass, rectal bleeding, anal ulceration or if they are age >60 y with iron deficiency anaemia.
If the test result is positive (that is, if hidden blood is found), a colonoscopy will need to be done to investigate further. Although blood in the stool can be from cancer or polyps, it can also be from other causes, such as ulcers, hemorrhoids, or other conditions.
This result means: blood was found in your poo sample. you do not necessarily have bowel cancer (the blood could be the result of something like piles) but you'll be offered an appointment to talk about having another test called a colonoscopy to look for the cause.
The higher the FIT value is above 20 the greater is the likelihood that there are polyps or a malignancy. FIT is also positive in patients with IBD as you would expect.
- persistent blood in your poo – that happens for no obvious reason or is associated with a change in bowel habit.
- a persistent change in your bowel habit – which is usually having to poo more and your poo may also become more runny.