The qFIT Test Explained: How It Works and Reading Your Results

If you've been offered a qFIT test, or you're thinking about arranging one yourself, you likely want to know what it involves before you commit. It's a simple check you do at home, using a small stool sample, to look for traces of blood that are too tiny to see. That blood can sometimes be an early sign of a problem in your bowel. Here's how it works, what your result means, and what to do next.

What is a qFIT test?

qFIT stands for quantitative faecal immunochemical test. It's an at-home stool test that looks for tiny traces of blood in your poo that you wouldn't be able to spot yourself, known as hidden or occult blood.

Blood in your stool can have a number of causes. Some are harmless, like piles. Others are more serious, and one of the reasons the qFIT test is so widely used is that hidden blood can be an early sign of bowel cancer, sometimes before any other symptoms appear.

A qFIT test doesn't diagnose bowel cancer, or any other condition. What it does is tell you whether blood is present, which helps determine whether you'd benefit from further investigation.

Bluecrest has delivered more than 1.3 million health assessments, and a check like this is one part of understanding what's going on inside your body.

How does the qFIT test work?

The test measures haemoglobin, the protein in red blood cells that carries oxygen around your body. If haemoglobin turns up in your stool, it points to bleeding somewhere in your bowel.

What makes the qFIT reliable is that it uses antibodies designed to recognise human blood specifically. That means it's less likely to give a misleading result because of something you've eaten, which was a known weakness of older stool tests.

Why would a bowel bleed in the first place? Anything that sticks out into the bowel, such as a polyp or a tumour, can be brushed by stool as it passes and bleed a little from time to time. That small amount of blood is the first, and sometimes the only, sign that something needs looking at.

qFIT and FIT: what's the difference?

If you're looking into a FIT test for bowel cancer, you may see both terms used and wonder which one you need. They're closely related.

A standard FIT gives a straightforward positive or negative answer, based on whether blood passes a set level.

A qFIT is quantitative, so it measures the actual amount of blood present, reported as micrograms of haemoglobin per gram of stool (µg Hb/g). That number allows for more precise, personalised decisions about whether you need any follow-up.

Who might consider a qFIT test?

A qFIT test can be useful if you've noticed symptoms affecting your lower bowel, such as:

• a change in your usual bowel habits
• blood in your stool
• ongoing abdominal pain
• unexplained weight loss
• tiredness that could point to anaemia

It's also chosen by people who simply want reassurance, or who have a higher risk because of a family history of bowel cancer.

If you're aged 50 to 74 and registered with a GP in England, the NHS Bowel Cancer Screening Programme automatically posts you a home test kit every two years. A private qFIT test can complement that, offering a check between screening rounds or before you become eligible, rather than replacing it.

Testing matters because bowel cancer is the fourth most common cancer in the UK, and outcomes are strongly linked to how early it's found. According to NICE, the chance of a complete cure is around 90% when it's caught at stage one, which is why getting the right people investigated quickly makes such a difference.

How to do a qFIT test at home

The test is designed to be quick and straightforward, with everything you need included in the kit. In most cases, it works like this:

1. Read the instructions in your kit before you start.
2. Collect a small stool sample using the stick attached to the sample bottle lid.
3. Return the stick to the bottle and click the cap shut.
4. Label the bottle clearly with your details, as an unlabelled sample may be rejected by the lab.
5. Post it back promptly using the packaging provided.

Wait until your period has finished before taking the test, and hold off if you have active piles or an anal fissure, or if you've recently had a procedure involving your bowel, such as a colonoscopy. Any of these can affect your result.

Reading your qFIT results

Because the qFIT is quantitative, your result is a number showing how much haemoglobin was found in your sample. That number is compared against a threshold. A result below the threshold is considered negative, while a result at or above it means further investigation is recommended.

A negative result suggests no significant bleeding was detected at the time of the test. A negative result isn't a guarantee, though. If you have symptoms that continue or get worse, speak to your GP, whatever your result shows.

A raised or positive result means blood was detected in your sample. This is where it's easy to worry, but a positive result does not mean you have cancer. It means there's bleeding that needs to be explained, and there are many possible causes, including piles, inflammatory bowel disease and polyps, as well as bowel cancer. The next step is to see your GP so the cause can be looked into.

What happens after a positive qFIT result?

If your result comes back raised, you'll be advised to see your GP, who may refer you for further investigation. That usually means a colonoscopy, a procedure that lets a specialist look directly at the lining of your bowel and find the source of the bleeding.

Most people who are investigated after a raised result turn out not to have cancer. The point of the process is to rule the serious causes out, or to catch them at a stage where they're far more treatable.

FIT-based testing has helped the NHS direct its colonoscopy capacity towards the people who most need it, so a referral means the process is doing its job.

Bowel cancer risk testing with Bluecrest

At Bluecrest, the qFIT is available as our Bowel Cancer Risk (qFIT) test. You can book it on its own or add it to one of our wider health checks, so you can look at your bowel health alongside other areas such as your heart, cholesterol and blood in a single appointment. You collect the sample at home, post it to our lab, and receive your results as part of your report.

If you'd like to look into your options, you can find out more about our Bowel Cancer Risk (qFIT) test, or explore our broader male cancer risk and female cancer risk health checks.

Live healthier for longer with Bluecrest health intelligence.

Frequently asked questions

Is a qFIT test the same as the NHS bowel screening test?

They use the same underlying method. The NHS Bowel Cancer Screening Programme sends people aged 50 to 74 in England a home FIT kit every two years. A private qFIT test lets you check at a time that suits you, for example between screening rounds or before you reach the eligible age.

Can a qFIT test detect bowel cancer on its own?

No. A qFIT test detects blood in your stool, which can be a sign of bowel cancer, but it can't diagnose it. A raised result means further investigation, usually a colonoscopy, is needed to find the cause.

How accurate is a qFIT test?

The qFIT is a sensitive test and is now central to how bowel cancer risk is assessed in the UK. Like any test, it isn't perfect, which is why a negative result shouldn't be treated as a guarantee if you have ongoing symptoms, and a positive result always leads to further checks rather than a diagnosis.

Do I need to change my diet before a qFIT test?

No. Because the test is designed to recognise human blood specifically, you don't need to avoid particular foods beforehand, unlike some older stool tests.

What's the difference between qFIT and FIT?

A standard FIT gives a positive or negative result. A qFIT is quantitative, measuring the exact amount of blood present, which allows for more precise decisions about whether follow-up is needed.