Bowel Screening

What is bowel screening?

Cancer screening involves testing for pre-cancerous or cancerous conditions in people who do not have any obvious symptoms of the disease. The aim of bowel screening 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 faecal occult blood test (commonly known as a FOBT) is a non-invasive test which detects microscopic amounts of blood in the bowel motion. Bowel screening requires people to complete a FOBT in their own home and send their completed FOBT to a pathology laboratory for analysis. People with a positive result, indicating blood in their bowel motion, are advised to consult their general practitioner to discuss further testing. In most cases this will involve a specialist looking inside the bowel using a special instrument. This procedure is known as a colonoscopy.

What are the symptoms of bowel cancer?

Bowel cancer can develop without any obvious symptoms. This is why it is important to screen. However, if symptoms exist they can include:

• Bleeding from the rectum or any sign of blood after a bowel motion;
• A recent and persistent change in bowel habit;
• Unexplained tiredness;
• Abdominal pain.

Why screen for bowel cancer?

In Australia in 2004 the risk of being diagnosed with bowel cancer by the age of 85 years was 1 in 10 for males and 1 in 14 for females, with the risk increasing sharply from the age of 45. Since 1982 the incidence of bowel cancer has been increasing slightly each year with 12,977 new cases diagnosed in 2004. Bowel cancer accounts for 10.6% of all deaths from invasive cancers, with 4,113 deaths in 2005, making bowel cancer the second most common cause of cancer-related death after lung cancer.

Who should be screened?

The current recommendation by the National Health and Medical Research Council is that all people over the age of 50 years should be screened every two years for bowel cancer using a faecal occult blood test.

National Bowel Cancer Screening Program

The National Bowel Cancer Screening Program (NBCSP) began in 2006. It currently offers free bowel screening to all Australians turning 50, 55 and 65 years of age. The Health Registers and Cancer Monitoring Unit of the AIHW monitors and reports on the performance of the NBCSP. The first annual NBCSP Monitoring Report is available only on the internet and can be accessed through our Publications portal.

In the first 18 months, the NBCSP sent over 715,000 FOBTs to eligible members of the population. Of these, 42% of people participated by returning a completed FOBT, however females were 19% more likely to complete the FOBT than men.

Blood was detected in 9.2% of all correctly completed FOBTS for males and 6.5% of all correctly completed FOBTS for females.

Of those who had results from a positive FOBT investigated by colonoscopy 6% were found to have cancer and 12% had pre-cancerous adenomas detected. A further 42% had polyps detected at colonoscopy but histopathology results were not yet available. The remaining 40% were found to have no cancer or adenoma.

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