Getting your FOB test results

Your FOB test results can be normal, abnormal or unclear.

About 98% of people will have a normal FOB test result. If your result is normal, you’ll be offered another FOB test in two years’ time.

About 2% of people will get an abnormal result. Getting an abnormal rest result is not a diagnosis of cancer. It may be caused by other conditions such as piles (haemorrhoids), a bleeding polyp or inflammatory bowel diseases. You will usually be advised to have an examination of your bowel, called a colonoscopy. This is to see what’s causing the abnormal results.

About 4% of people may receive an unclear result at first. If you have an unclear test result, it doesn’t mean you have bowel cancer. It just means you need to do the test again. You might also need to repeat the test if there’s been a technical problem in the laboratory or if the FOB kit has been damaged for any reason.

When will the test results be ready?

You should get the results of your FOB test in writing within two weeks of the test being received for analysis at the laboratory. Your GP will also get a letter with your results. Waiting for your results may be an anxious time for you and it may help to talk things over with a relative or close friend or one of our cancer support specialists.

The three possible FOB test results are:

  • normal
  • abnormal
  • unclear.

Normal result

About 98 out of 100 people (98%) will have a normal result. A small number of people will have repeated the test due to an unclear result the first time. If your result is normal, you'll be invited to do an FOB test again in two years’ time, as long as you're still within the invitation age range. If you are older than this you can continue to be screened every two years by requesting a screening kit.

The letter will include information about the symptoms of bowel cancer, so that you know what to look out for. If you're worried about any symptoms that develop between your two-yearly screening tests, you should make an appointment with your GP.

Abnormal result

Around 2 in 100 people (2%) will have an abnormal result. Sometimes, someone with an abnormal result will have repeated the test due to a previous unclear result. If your result is abnormal, you'll be sent a letter and an appointment to see a specialist practitioner at your local hospital or screening centre. Your appointment should be arranged within a week of receiving your letter. Your GP will also be told your results.

Having an abnormal result is not a diagnosis of cancer. The abnormal result may be caused by conditions other than cancer, such as piles (haemorrhoids), a bleeding polyp or inflammatory bowel diseases, such as Crohn's disease or ulcerative colitis. You will usually be advised to have an examination of your bowel, so that a diagnosis can be made.

Unclear result

Around 4 in 100 people (4%) may initially receive an unclear result. This means that there was a hint of blood in the sample, but not enough to give an abnormal result. An unclear result can be caused by conditions such as piles (haemorrhoids). Having an unclear result doesn't mean you have bowel cancer: it simply means that the FOB test needs to be repeated. Most people who repeat the FOB test go on to receive a normal result.

You'll be sent a new FOB test kit. You should follow the instructions and return the samples as before.

If you have a second or third unclear FOB test, or an abnormal result, you'll be given an appointment to see a specialist screening practitioner. The appointment will be at your local hospital or screening centre and should be within a week of the letter telling you the FOB test result.

The practitioner will explain what your result means and answer your questions. They will discuss having a colonoscopy and give you a detailed explanation of the procedure, including its benefits and risks. They will also assess whether you're fit to have a colonoscopy.

A colonoscopy isn't appropriate for everyone. If you're not able to have one, you may be offered a different investigation, such as a CT colonography or barium enema.

If the result of your repeat test is normal, you may be sent another kit just to confirm the result. Other reasons you may be asked to repeat the FOB test are:

Technical failure

Sometimes there's a technical problem when your samples are tested in the laboratory. If this happens you'll be sent a letter and another test kit to collect more samples.

Spoilt kit

Sometimes the FOB kit can't be tested in the laboratory because it hasn't been used properly or has been damaged. If this happens you'll be sent a letter and a replacement kit.

Back to Bowel screening

The bowel

The bowel is part of our digestive system and is made up of the small bowel and the large bowel.

What is bowel cancer screening?

Bowel screening can find bowel cancer at a very early stage, when it has the best chance of being treated.

What to do with your FOB test kit

This test checks bowel motions for tiny amount of ‘hidden blood’. It is not a test for cancer, but can indicate whether further tests are needed to examine the bowel.

Your feelings about bowel screening

People react differently to their bowel screening results. There is no right or wrong way to feel.


A colonoscopy is a way of examining the lining of the bowel from the inside.

Virtual colonoscopy (CT colonography, CT enema, CT pneumocolon)

This test uses a CT scanner to create a picture of the bowel.

Barium enema

This is a special x-ray of the large bowel.

Common questions about bowel screening

You may have lots of questions about bowel screening. You can ask your GP if you’re unsure of anything.