Screening is the testing of people to detect disease early before there are any obvious symptoms. Research shows that early screening for bowel cancer does help reduce death rates by finding and treating bowel cancer early. Screening saves lives. Simple!
The aim of bowel screening is to find polyps in people who have no symptoms and is important because bowel cancer can develop without any early warning signs. Detected early, 90% of bowel cancers can be treated successfully. Currently in Australia, fewer than 40% of bowel cancers are caught in the early stages.
Medical guidelines in Australia recommend that people 50 years and over with no family history of bowel cancer and no symptoms should be screened for bowel cancer every 1 to 2 years.
The most commonly used screening tools that help to identify whether bowel cancer is present include:
Faecal occult blood test (FOBT)
Immunochemical FOBT is considered the 'gold standard' for bowel cancer screening. It is simple, non-invasive testing that can be done in the privacy of your own home. It is used to detect hidden blood in the bowel motion (or stool) often released by polyps or bowel cancers. Screening with these tests can reduce your chance of dying from bowel cancer by up to 33%.
The completed test is returned to the pathology service by mail, and the results are sent confidentially to you and your nominated doctor. A positive result does not always mean there is cancer present, but the cause of bleeding should be investigated by colonoscopy.
The immunochemical FOBT requires no faecal handling, no change in diet or medications and has no side-effects.
Screening with an immunochemical FOBT is recommended for Australians every 1 to 2 years for those:
- Aged 50 and over
- With no symptoms
- With no family history of bowel cancer or polyps
What do my FOBT results mean?
- A negative result means that no blood has been detected in the samples provided. This does not mean that you do not have or won’t develop bowel cancer in the future, so it's important to repeat the test every 1 to 2 years.
- A positive result means blood has been detected in your sample. About one in 14 people will have a positive FOBT result. Bleeding can be caused by a number of conditions including polyps, haemorrhoids or inflammation, and may not necessarily be related to cancer. However, if blood is detected, further investigation with colonoscopy is needed to find the cause.
A colonoscopy is a comprehensive and invasive procedure that allows a doctor to examine the entire length (rectum and colon) and lining of the bowel.
Prior to the colonoscopy, a bowel preparation is required to clean the bowel. This is a drink taken on the day before the procedure which will empty the bowel so that it can be seen clearly. An enema may also be required (see ‘Sigmoidoscopy’).
A long, flexible and lighted tube (colonoscope) is inserted into the anus, then pushed gently up in the rectum and colon. If polyps or anything unusual is found during the procedure, they will be removed for further examination under a microscope. This is called a biopsy. Patients are usually given a sedative to make them feel relaxed or sleepy during the procedure, which takes 15-20 minutes.
There may be some discomfort but rarely pain. The most common side effect of a colonoscopy is temporary wind pain and flatulence – caused by the air pumped into the bowel during the procedure. More serious, but rarer, complications may include tearing the lining of the bowel or bleeding. These risks will be discussed with the patient by the doctor.
Discuss these screening options with your GP to make a decision on the best screening strategy for you based on your own medical history.
Strong family history or other risk factors?
If you have identified risk factors for polyps or bowel cancer, you may need to start screening at an earlier age. Speak to your GP to discuss the benefits of increased or earlier bowel screening based on your own circumstances.
No screening test is 100% accurate so it is important to be screened regularly. If you are worried that you might have symptoms of bowel cancer you should see your GP so the cause can be found and treated, even if you have recently had a bowel screening test.
And remember, you should never be told you are too young to have bowel cancer. While bowel cancer is more common in people aged 50 and over, no age group is immune. If you have any questions or concerns, please speak to your GP.