Bowel Cancer Screening

Bowel cancer (also known as colon cancer) is common in Australia and the western world. Approximately 1 out of 20 people will develop a bowel cancer in their lifetime and there are approximately 13,000 new cases diagnosed in Australia every year. This number is increasing every year.

Even though this is a very common problem, it is relatively uncommon in people younger than 40 years of age. Less than 1% of people diagnosed with bowel cancer are under the age of 35. However, it becomes much more common in people over the age of 50 years.

Essentially, bowel cancer screening is testing a group of people (who have an increased risk due to their age) for bowel cancer even though they have no symptoms at all. In Australia, bowel cancer screening is offered through the National Bowel Cancer Screening Program to all people 50 years and older.

If you have symptoms that you have noticed yourself, such as visible bleeding or a major change in your bowel habit, you should not complete a screening test, but rather, see your GP directly for a review.

The National Bowel Cancer Screening Program and Faecal Occult Blood Testing (FOBT)

This is an Australia wide program run by the Federal Department of Health, that offers free screening for bowel cancer to all people from the age of 50 years up to 74 years. The program has been proven to decrease the risk of dying from bowel cancer by up to 25% for those who participate in it.


The National Bowel Cancer Screening Program involves a test called a Faecal Occult Blood Test (abbreviated simply to FOBT) that is collected at home and sent back to the program for analysis. It is painless and easy to do. It involves collecting a sample from two separate bowel motions that occur within a day or two of each other. The aim of the test is to detect very small, microscopic amounts of blood in your bowel motions. These small amounts of blood are not even visible to the naked eye.

FOBT is offered to all people from the age of 50 years and onwards. From 2018 and onwards, it is planned to be offered to all people every 2nd year but up until then, it is offered between every 2nd to 4th year depending on your age.

It is very important to do this test if the opportunity is offered to you, as FOBT can detect bowel cancer at an early stage but more importantly, it can also detect early changes in your bowel such as polyps. Removing polyps has been shown to decrease your risk of bowel cancer in future years as some polyps can develop into a cancer as time goes on. If blood is detected, then it is recommended you go on and have a further test to better look at the lining of your bowel. The most common next test for a positive FOBT is a colonoscopy although there are other alternatives that may be recommended instead, depending on your individual situation.

Can I undergo FOBT even if I am not offered the test with the screening program?

You can arrange to undergo FOBT through your GP (via private pathology services) or your pharmacist (via private programs such as Rotary’s “BowelScan”) if you wish. Performing an FOBT younger than the age of 50 is not normally necessary, but it is recommended that from 50 onwards and up until 74, a second yearly test is the best type of screening as a minimum. After 2018, this should occur every second year from the age of 50 onwards with the national program but until then, it is recommended privately arranged screening is best done for the years when a government based test is not offered.

What should I do if my FOBT comes back as positive?

If your FOBT detects blood in your bowel motions, you should see your GP as soon as possible. Your GP will then refer you to an appropriate specialist who performs colonoscopy, for further assessment.

Whilst it is very concerning if your FOBT comes back being positive, it is important to remember that the vast majority of people with a positive FOBT do not have bowel cancer. Many people (possibly as high as 50%) can have polyps however and many will have no abnormality at all. It is impossible to tell from a positive FOBT which people could have a cancer, a polyp or nothing at all, but it is very important to see a specialist at that point so a colonoscopy or a similar test can be done.

This specialist can be either a surgeon (general and colorectal surgeons) or a gastroenterologist. The important point here is that whoever you see, that person should be someone who is formally accredited to perform colonoscopy and working within a team that manages bowel cancer frequently.

How quickly should I see a specialist if my FOBT is positive?

Ideally, it is recommended that a patient with a positive FOBT is seen by a specialist within weeks and that a colonoscopy is performed within 30 days of that consultation. If you have a positive FOBT and have been referred to see Dr Betros, you should notify the booking staff of this. An urgent priority appointment will be arranged to minimise any delay in arranging a colonoscopy if needed.

Do I need to do an FOBT if I have “bowel symptoms”?

If you have any symptoms such as rectal bleeding, rectal mucous, a prolonged change in your bowel habit, unexplained weight loss or abdominal pain that does not go away, you should consult with your GP prior to doing an FOBT. Many of these symptoms may require a colonoscopy even if the FOBT were to come back negative.

An FOBT is only useful if you have never had any symptoms. Once you have developed any symptoms like those described above, you are best off seeing your GP to discuss having the symptoms investigated with a colonoscopy or similar test.

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