Screening for bowel cancer 

Bowel cancer can be present for a long time before any symptoms appear. If it's detected before symptoms appear, it's easier to treat and there's a better chance of surviving the disease.

To detect cases of bowel cancer sooner, the NHS Bowel Cancer Screening Programme was introduced in England in 2006. Men and women aged 60-69 registered with a GP will automatically be sent an invitation for screening through the post every two years.

The screening programme is also being extended in England to those aged 70 to 74. Screening centres in England are rolling out the extension once their two-year screening invites have completed.

Bowel cancer screening is also being carried out in the rest of the UK, but in Scotland people aged 50-74 are invited for screening.

People over 70 can also request a screening kit by calling the freephone helpline 0800 707 6060 (you’ll need your NHS number to hand).

Routine screening isn't offered to people less than 60 years of age, so if you think you may be at an increased risk of bowel cancer and you are not yet eligible for screening, it may help to speak to your GP about your options and what you should be looking out for.

Screening consists of a home testing kit, called an FOBt (faecal occult blood test) kit. The kit arrives through the post when screening is due. The kit is used to collect tiny stool samples on a special card.

The card is then sealed in a special hygienic freepost envelope and sent to a laboratory where it will be checked for traces of blood that may not be visible to the naked eye, but may indicate a problem.


Results are received in writing within two weeks of sending in the test kit. There are three types of result:

  • Normal – when no blood was found in the samples. Screening will be offered again in two years’ time.
  • Unclear – when there were possible traces of blood that could be caused by factors other than cancer, such as haemorrhoids (piles) or stomach ulcers. If you have an unclear result, you will be asked to repeat the test kit up to two more times.
  • Abnormal – when blood was definitely found in the samples. Again, this could be due to something such as piles or bowel polyps. If you have an abnormal result, you will be offered an appointment with a specialist nurse to discuss having an examination of the bowel, called a colonoscopy (see below).

Only half of all bowel cancers are picked up by the screening test. The ones missed by the screening test cause symptoms at a later date. If you develop symptoms after a negative test, try the bowel cancer symptom checker to see whether you need to see your GP.


A colonoscopy is an investigation of the lining of the large bowel (colon). A thin, flexible tube with a camera on the end (colonoscope) is passed into your rectum and guided around the bowel.

Only around two in every 100 people completing the FOBt kit will have an abnormal result and will be offered a colonoscopy. Of those who have a colonoscopy, only about one in 10 will have cancer.

New screening test

As well as the FOBt described above, an additional screening test is being rolled out by 2016. This involves inviting people at age 55 to have a one-off flexible sigmoidoscopy test to examine the lower bowel with a camera.

A flexible sigmoidoscopy is a similar test to a colonoscopy, although it cannot be used to see quite as far into the bowel. If the test shows polyps in your bowel, the person will then be offered a full colonoscopy (see above) to investigate further.

Both FOBt and flexible sigmoidoscopy screening tests have been shown to reduce the risk of dying of bowel cancer.

See diagnosing bowel cancer for more information about colonoscopies and sigmoidoscopies.

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Page last reviewed: 02/09/2014

Next review due: 02/09/2016