Bowel cancer screening - Diagnosis

If you get a positive result from any of these screening tests, this might make you very anxious. But a positive test doesn't mean you definitely have cancer. You will need more tests to check for cancer cells.

You'll be sent for a colonoscopy test if you get a positive result from any of these tests:[1]

Digital rectal examination
Faecal occult blood test or faecal immunochemical test
Flexible sigmoidoscopy
Double-contrast barium enema
Computed tomography colography.

Colonoscopy is a very thorough test for bowel cancer, because it can see the full length of the bowel. That's why doctors use it if you have had a positive result on another test.

If the colonoscopy test finds any polyps, these can be removed during the test. Having polyps doesn't mean you have cancer now, or that you will get it later. But bowel cancer usually starts with polyps. So you should be screened more regularly from now on.

If the colonoscopy test finds any abnormal-looking areas in the bowel, the doctor will remove a small piece of tissue during the test. Doctors call this taking a biopsy.

This tissue is then sent to a laboratory, where it is examined under a microscope that can show up cancer cells.[2]

If the examination finds cancer cells, you will be referred to a doctor who specializes in bowel cancer.

The doctor will need to do some further tests to find out how big the cancer is and whether it has spread. This will help him or her plan the best treatment for you.[3]

The main treatments for bowel cancer are surgery, radiotherapy and treatment with anti-cancer drugs, known as chemotherapy.[3] To find out more about how bowel cancer is diagnosed and treated, see our pages about Colon cancer.

If you have a negative result from your test, it means the test did not find any signs of cancer. This is reassuring. But remember that no test is 100 percent accurate.

You should still see your doctor if you have any symptoms that could mean bowel cancer. These include:[4]

Repeated bleeding from your back passage
Seeing blood in your stools
A change in your bowel habits that lasts for more than six weeks. This could be loose stools and needing to go to the toilet more often, or bad constipation
Bad pain in your tummy
Unexplained weight loss or severe tiredness.

To learn more, see Colon cancer.

References

Centers for Disease Control and Prevention. Colorectal cancer screening. March 2006. Available at http://www.cdc.gov/colorectalcancer (accessed on 16 May 2006).
American Cancer Society. Colon and rectum cancer: how is colorectal cancer diagnosed? March 2006. Available at http://www.cancer.org (accessed on 5 May 2006).
National Cancer Institute What you need to know about cancer of the colon and rectum: staging Available at http://www.cancer.gov/cancertopics/wyntk/colon-and-rectum (accessed on 5 May, 2006)
NHS Bowel Cancer Screening Programme. A new NHS cancer screening programme. Available at http://cancerscreening.org.uk/bowel.

Glossary

biopsy: This is when doctors remove some tissue from a part of the body, so that it can be examined under a microscope.

This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.