Bowel cancer screening
Peer reviewed by Dr Colin Tidy, MRCGPLast updated by Dr Hayley Willacy, FRCGP Last updated 19 Jul 2023
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In this series:Bowel cancerFaecal immunochemical testSigmoidoscopyColonoscopyCT colonographyBowel polyps
Bowel (colorectal) cancer is common. The outlook (prognosis) and chance of cure are much better if this cancer is detected at an early stage rather than at a later stage. A screening programme operates in the UK for certain age groups.
The aim is to offer an easy screening test to detect bowel cancer when it is at an early stage and before symptoms start. Some people outside the normal screening age who have a high risk of developing bowel cancer are offered extra screening tests.
In this article:
See the separate leaflet called Colon, Rectal and Bowel Cancer (Colorectal Cancer).
Continue reading below
What is bowel cancer screening?
Screening means looking for early signs of a particular disease in otherwise healthy people who do not have any symptoms. If certain diseases are picked up early, the disease can be cured.
Bowel cancer screening aims to detect bowel cancer at an early stage when there is a good chance that treatment will cure the cancer. There are two methods of screening for bowel cancer:
A test to detect traces of blood in your stools (faeces). This is called the faecal immunochemical test (FIT).
An examination of the inside of the bowel by a test called flexible sigmoidoscopy.
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As a nation, we're doing very well health-wise. In the last 50 years, average life expectancy has increased by almost 10 years in the UK. So today, the average man lives until 79 years old and the average woman to almost 83. A lot of that is down to improved treatments - for heart attack, stroke, cancer and more. But much of this good news is down to screening - which lets doctors pick up conditions early, when treatment is more likely to be effective.
by Dr Sarah Jarvis MBE, FRCGP
Cervical screening
Cervical screening tests (smear tests) are available to women and people with a cervix aged 25-64 years in the UK. The tests are done to prevent cervical cancer by finding abnormalities that can, with relatively simple treatments, be prevented from progressing to cervical cancer. Cervical screening tests are not used to diagnose cancer. The information below applies specifically for NHS patients in England. However, the screening programme is very similar for each country. For specific information about screening programmes in Scotland, Wales and Northern Ireland, see the Further Reading links at the end of this leaflet.
by Dr Colin Tidy, MRCGP
Who is offered bowel cancer screening?
Across the UK, everyone between the ages of 60 and 74 are eligible for bowel cancer screening. However, for those under 60 the NHS bowel cancer screening programme is different across England, Scotland, Wales and Northern Ireland.
England
If you're between 60 and 74 years, you'll automatically be invited to use a home testing kit (a faecal immunochemistry kit or FIT) every two years.
The screening is expanding to those aged 50-59 years and is being rolled out from April 2021 over a 4 year period.
In most but not yet all areas, anyone aged 55 is invited for a one-off screening with flexible sigmoidoscopy.
If you're aged 75 or over, you can ask for a home testing kit every two years by calling the bowel cancer screening helpline on 0800 707 60 60.
Scotland
If you're between 50 and 74 years, you'll automatically be invited to use a home testing kit (a faecal immunochemistry kit or FIT) every two years.
People aged over 74, can request a screening kit by contacting the bowel cancer screening programme on 0800 012 1833.
Wales
If you're between 55 and 74 years, you'll automatically be invited to use a home testing kit (a faecal immunochemistry kit or FIT) every two years.
The screening is being expanded to those aged 50-54 years over the coming years.
For more information you can contact the Bowel screening Wales helpline on 0800 294 3370.
Northern Ireland
If you're between 60 and 74 years, you'll automatically be invited to use a home testing kit (a faecal immunochemistry kit or FIT) every two years.
For more information about the bowel cancer screening programme in Northern Ireland contact the helpline on 0800 015 2514.
FIT screening replaced the old faecal occult blood (FOB) test from June 2019 in Wales and from later in 2019 in England. The FIT is easier to use than the FOB and is more accurate in detecting potential cancers.
When should I screen for bowel cancer?
The American Cancer Society recommends that people who do not have an increased risk of colon cancer start regular screening at age 45. This can be done either with a stool-based test, or with a test that looks at the colon and rectum - a bowel scope.
People who are in good health with a life expectancy of more than 10 years should continue regular colorectal cancer screening through the age of 75. Between 76 and 85 years, the decision to be screened should be based on a person's preferences, life expectancy, overall health, and prior screening history. People over 85 should no longer have colorectal cancer screening.
Continue reading below
Bowel cancer screening kits
Faecal immunochemical home test
The FIT kit consists of a small plastic container with a stick attached to the lid. People collect samples using the following steps.
Scrape the tip of the stick along the bowel motion.
Put the stick back into the bottle.
Click the bottle shut.
Put the used kit into the return freepost packaging and send for analysis.
You will get one of two screening results. These are:
Normal result: no significant level of blood detected.
Abnormal result: blood detected and the individual is offered an appointment to discuss having a colonoscopy.
A colonoscopy is a test in which a long, thin, flexible telescope (a colonoscope) is passed through your back passage (rectum) into your large bowel (colon). In this way the whole of your colon and rectum can be looked at in detail. An alternative to colonoscopy is a CT colonography.
Results will be sent to participants within two weeks of the kit arriving for analysis. Your GP will be notified of all test results.
There are various reasons other than bowel cancer for having a positive test. For example, some medical conditions including piles (haemorrhoids) can lead to a positive test. Most people with a positive test will NOT have bowel cancer.
Bowel cancer screening can also detect growths (polyps) on the inner lining of the bowel. These are not cancers but may develop into cancers over time. They can easily be removed, which makes it less likely that bowel cancer will develop.
Following a colonoscopy after screening:
About 5 in 10 people who have a colonoscopy will have a normal result.
About 4 in 10 will be found to have a polyp, which if removed may prevent bowel cancer from developing.
About 1 in 10 people will be found to have bowel cancer.
Note: a normal test result does not completely rule out bowel cancer. It is therefore important to be aware of the symptoms of bowel cancer and to see your doctor if you are concerned.
Bowel cancer screening with flexible sigmoidoscopy
What is flexible sigmoidoscopy?
The sigmoid colon is the final portion of the large bowel (colon) which is joined to the back passage (rectum). A flexible sigmoidoscope is a small bendy tube with an attached light source, about the thickness of a pen. See also the separate leaflet called Sigmoidoscopy.
What is screening with flexible sigmoidoscopy?
It has been proposed that a routine flexible sigmoidoscopy test should be offered to all adults around the age of 55. This is because most bowel polyps and bowel cancers develop in the rectum, sigmoid colon or lower descending colon.
Bowel (colonic) polyps are small non-cancerous (benign) growths on the inside lining of the colon or rectum. They get more common as we become older. They usually cause no symptoms or problems. However, if a polyp is found, it is usually removed. This is because there is a small risk of a colonic polyp developing into a bowel cancer after several years.
Continue reading below
Bowel cancer screening tests for younger people with increased risk
Some people have a higher than normal risk of developing bowel cancer. This is because some diseases cause an increased risk of developing bowel cancer. Also, relatives of people with certain diseases have an increased risk of developing bowel cancer.
Therefore, some people are offered regular screening tests, often from a young age. The tests done are different from the regular screening programme. These groups of people offered extra screening tests include:
People with certain inherited conditions. These are rare conditions. They include:
Familial adenomatous polyposis (FAP).
Hereditary non-polyposis bowel cancer (HNPCC).
Peutz-Jeghers syndrome.
Juvenile polyposis syndrome.
Close relatives of people with FAP or HNPCC.
People with a strong family history of first-degree relatives (mother, father, brother, sister, child) who have had bowel cancer. In particular, if the cancer developed in a close relative under the age of 45 years.
People with ulcerative colitis or Crohn's disease affecting the large bowel (colon) or back passage (rectum).
People with a condition called acromegaly.
People who have had one or more bowel growths (polyps) removed.
People who have had bowel cancer in the past.
The age at which screening starts, the type of tests offered and the frequency of the tests depend on the level of increased risk. The different diseases and family associations mentioned above have varying levels of risk. The tests may include regular colonoscopy or some specialised scans.
If you have a disease or family history that causes an increased risk of developing bowel cancer, your doctor will advise on the type of tests recommended and their frequency. The British Society of Gastroenterology guidelines in 'Further Reading and References' below may also be of interest.
Further reading and references
- Colonoscopic surveillance for prevention of colorectal cancer in people with ulcerative colitis, Crohn's disease or adenomas; NICE Clinical Guideline (March 2011 - last updated September 2022)
- Bowel cancer statistics; Cancer Research UK
- NHS Bowel Cancer Screening Programme
- NHS bowel cancer screening (BCSP) programme; GOV.UK. January 2015, last updated March 2021.
- Bowel screening; NICE CKS, May 2019 (UK access only)
Continue reading below
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 17 Jul 2028
19 Jul 2023 | Latest version
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