Colorectal Screening (Bowel Cancer Screening) at Cardiff and Vale Hospitals

What is colorectal screening?

Colorectal screening, also called bowel cancer screening, checks for early signs of bowel cancer before you have any symptoms. In the UK, this usually means a home test that checks for tiny traces of blood in your poo, though a colonoscopy can also be used to look directly inside your bowel.

Why might I need colorectal screening?

You may be invited for screening, or may want to ask about it, if:

• you're aged 50 to 74, when you'll automatically be invited every 2 years as part of the NHS bowel cancer screening programme
• you're 75 or over and would like to keep being screened; you can request a kit yourself every 2 years
• you have a higher risk of bowel cancer, for example because of a family history, inflammatory bowel disease, or a genetic condition such as Lynch syndrome, which may mean earlier or more frequent testing.

What are the benefits of colorectal screening?

• It can find bowel cancer before you have any symptoms, when treatment is more likely to be effective
• It can also find polyps, small growths that aren't cancer but can turn into cancer over time; removing them lowers your future risk
• Regular screening reduces your risk of both getting and dying from bowel cancer
• The home test is simple and can be done in private, without needing to visit a clinic.

Are there different types of colorectal screening?

The NHS programme uses a home test called the FIT (faecal immunochemical test), sent through the post every 2 years. If blood is found, you'll usually be offered a colonoscopy, a test that looks directly inside your bowel using a camera, to find out the cause of the blood.

In some other countries, colonoscopy itself is used as the main screening test, often repeated every 5 to 10 years from around age 50, rather than a home test being the first step. In England, people with Lynch syndrome are invited for surveillance colonoscopies via the NHS bowel cancer screening programme.

How do I prepare for colorectal screening?

For the home test:

• use a clean, disposable container to collect your sample, without letting it touch the toilet water
• if you have periods, it's best to collect your sample when you're not bleeding; avoid the 2 days before or after your period too
• call the free helpline if you're unsure whether to use the kit, for example if you've had bowel surgery or have a stoma.

What happens during colorectal screening?

Here's what typically happens with the home test:

1. Write the date on the sample bottle.
2. Use a clean container to catch a small amount of your poo, without letting it touch the toilet water.
3. Scrape the sample stick along your poo until all the grooves are covered, then put it back in the bottle and close the lid tightly.
4. Wash your hands, then put the sealed bottle in the envelope provided.
5. Post the envelope as soon as you can; postage is free and no stamp is needed.

What happens after colorectal screening?

You'll usually get your result within 2 weeks, by letter. Most people (around 97 to 98 in 100) are told no further tests are needed, and they'll be invited for screening again in 2 years.

Around 2 to 3 in 100 people are told further tests are needed, because some blood was found in the sample. This doesn't necessarily mean cancer. You'll be offered an appointment with a specialist nurse to talk through your results and discuss having a colonoscopy to find the cause.

What are the risks of colorectal screening?

• No screening test is completely reliable. The test could miss a polyp or cancer if it wasn't bleeding at the time you did the test
• A positive result doesn't always mean cancer; blood in your poo can have other, more common causes such as piles, fissures or polyps
• If you need a follow-up colonoscopy, it is generally a very safe procedure. Common mild side effects can include abdominal bloating, cramps, minor bleeding, after-effects of sedation or changes in bowel habits. However, there's a small, rare risk it could cause severe bleeding, a small tear in your bowel, infection or a reaction to your anaesthetic. A recent national audit of over 20,000 colonoscopies recorded no deaths from the procedure.