National Bowel Cancer Screening Program's Information Booklet

Screening for bowel cancer

Page last updated: 21 February 2020 (this page is generated automatically and reflects updates to other content within the website)

What is screening?

Screening involves testing for bowel cancer in people who do not have any obvious symptoms of the disease. The aim is to find polyps or cancer early when they are easier to treat and cure.

Bowel cancer can develop without any early warning signs.

The cancer can grow on the inside wall of the bowel for several years before spreading to other parts of the body. Often very small amounts of blood leak from these growths and pass into the bowel motion before any symptoms are noticed.

A test called a Faecal Occult Blood Test (FOBT) can detect small amounts of blood in your bowel motion. Although no screening test is 100 per cent accurate, the FOBT is at present the most well researched screening test for bowel cancer.

The National Health and Medical Research Council (NHMRC) recommend screening with an FOBT every two years from the age of 50 years5.

If you develop any of the symptoms of bowel cancer or discover a family history of bowel cancer you should contact your doctor as soon as possible to talk about the type of testing that is most suitable for you.

What if I’ve been tested for bowel cancer in another process?

If you:
  • have had a bowel condition in the last 12 months which is currently under treatment; or
  • have had a recent colonoscopy (anytime in the last 5 years); or
  • are scheduled for a colonoscopy in the next few weeks;
then you may wish to discuss your participation in the screening program with your doctor. Please advise the Information Line (1800 118 868) if your doctor recommends that you do not need to participate in the program.

What does the FOBT involve?

The FOBT is a simple test that you do at home before sending samples to a pathology laboratory for analysis. The test is quick, easy and painless. To increase the chances of detecting tiny amounts of blood in your bowel motion, you will need to take samples from two separate bowel motions. Ideally, samples should be collected as close together as possible and preferably no more than 2-3 days apart.

The accuracy of the results can be affected by temperature and by the time from sampling to analysis. Taking the samples as close together as you can, storing them correctly and returning them quickly for analysis will ensure that your result is as accurate as possible. If it takes longer than 14 days from when you take the first sample to when your samples reach the pathology laboratory, you will be sent another kit to complete.

The FOBT kit includes an instruction sheet, and you should read this carefully before doing the sampling.

Once you have collected the samples, send them to the pathology laboratory for testing in the reply paid envelope provided in the kit. When sending in your samples make sure you include your signed Participant Details Form. You are encouraged to nominate your doctor on the form. If you don’t have a regular doctor, but attend a clinic or service (such as an Aboriginal Medical Service) for health care, then you can nominate that service.

The pathology laboratory will send your test results to you and your doctor/health service (if nominated). If you have a positive test result, you will need to discuss the result with your doctor/health service.

What if I need another test kit?

If you lose or damage your test kit and need a replacement, please contact the Information Line on 1800 118 868.

What if I cannot understand the test’s instructions?

Call the FOBT Helpline on 1800 738 365 if you are unsure how to do the test. They will talk you through it step by step.

How reliable is the test?

No screening test is 100 per cent accurate. As with most tests, the sooner the samples can be analysed, the more accurate the result. Taking the samples as close together as you can, storing them correctly and posting them promptly will ensure that the most accurate results are obtained.

Blood starts to break down once it leaves the body. The liquid in the collection tube acts as a preservative for blood. Certain conditions can cause blood to break down at a faster rate and, once the blood breaks down, it is harder to detect in the screening process. This may result in a ‘false negative’. Samples that are exposed to high temperatures for extended periods, or delayed in analysis, may be affected in this way.

To reduce the breakdown of any blood in the samples, it is important not to expose them to high temperatures and to complete the test promptly.

Can I place my samples in the fridge?

Yes. Given the tiny amount of sample required and the four protective coverings (the sampling tube, the transport tube, the plastic ziplock bag and the reply paid envelope) there should be no risk of contamination with other contents of your fridge.

The fridge provides the most stable conditions for your sample but Do Not Freeze.

What will happen to my FOBT results?

The results will be sent to you, your doctor (if you have nominated one) and also to the Program Register about two weeks after you post your completed test to the laboratory.

If you opt off the Program after you have completed a FOBT and sent it for analysis, the results of the test will still be sent to you and your doctor (if nominated).

What does the FOBT show?

The FOBT shows whether or not blood was found in your samples.

If no blood is found in the samples you send to the laboratory, your FOBT result is negative. However, this does not mean that you do not have or can never develop bowel cancer, as some bowel cancers do not bleed or only bleed on and off. The NHMRC recommends that
you have an FOBT every two years from the age of 50 years6.

If you develop any symptoms of bowel cancer after receiving a negative result, see your doctor immediately.

If blood is present in the samples you send to the laboratory, your FOBT result is positive. About one in 13 people will have a positive result, indicating the presence of blood7. This may be due to conditions other than cancer, such as polyps, haemorrhoids or inflammation of the bowel, but the cause of the bleeding needs to be investigated. If blood is detected, you will be asked to contact your doctor to discuss the result.

5 The National Health and Medical Research Council (NHMRC) Clinical Practice Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer (2nd edition, December 2005), p 38.
6 ibid, p 38.
7 AIHW 2012. National Bowel Cancer Screening Program: annual monitoring report: Phase 2, July 2008-June 2011. Cancer Series NO. 65. CAN 61. Canberra: AIHW, p 25.