National Bowel Cancer Screening Program's Information Booklet

About bowel cancer

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

What is bowel cancer?

Bowel cancer is a malignant growth that develops most commonly inside the large bowel. Most bowel cancers develop from tiny growths called polyps. Polyps look like small spots on the bowel lining or like cherries on stalks. Not all polyps become cancerous. If polyps are removed, your risk of bowel cancer is reduced.

The beginnings of bowel cancer

Image showing the malignant growth inside the large bowel. Image showing Blood vessel, Boundary, Normal cells, Abnormal cell, Abnormal cells multiply, Polyp and Bowel Cancer

How common is bowel cancer?

Bowel cancer is one of Australia’s most common cancers, especially for people over 50. In 2009 about 14,410 new cases were diagnosed. It is also a major cause of cancer deaths, with around 80 Australians dying from bowel cancer each week.

During 2010, lung, bowel, prostate and breast cancer were the most common causes of cancer related death in Australia, as shown in Figure 1.

Figure 1: Number of deaths from the most commonly occurring internal cancers in Australia, 2010

Number of deaths from the most commonly occurring internal cancers in Australia, 2010. For detailed description please refer to the descriptive link next to the image. Description of the image

Australian Institute of Health and Welfare & Australasian Association of Cancer Registeries 2012. Cancer in Australia: an overview, 2012. Cancer series no. 74. Cat. No. CAN 70. Canberra: AIHW

What causes bowel cancer?

It is difficult to give one reason, but for most people it is their age and diet that contribute to the development of bowel cancer.

What are the symptoms of bowel cancer?

Bowel cancer can develop without any obvious symptoms. This is why it is important to screen.

Symptoms can include:
  • bleeding from the rectum or any sign of blood after a bowel motion
  • a recent and persistent change in your bowel habit, for example if you have looser bowel motions, severe constipation and/or if you need to go to the toilet more often than usual
  • unexplained tiredness (a symptom of anaemia) or weightloss
  • abdominal pain.


If you notice any of these symptoms, it does not mean that you have bowel cancer, but it is very important that you discuss them with your doctor.

Can bowel cancer be cured?

Bowel cancer is one of the most curable types of cancers if found early. That is why completing the free screening test sent to you is so important.

Can bowel cancer be prevented?

While no cancer is completely preventable, you can lower your risk of bowel cancer by eating a healthy diet, exercising regularly, reducing your alcohol consumption and quitting smoking.

It is never too late to make changes to your diet and lifestyle. If you would like more information on a healthy diet, talk to your doctor or see the program’s web site at Cancer Screening website.

Who is at risk of bowel cancer?

Both men and women are at risk of developing bowel cancer.
The risk is greater if you:
  • are aged 50 years and over – your risk increases with age;
  • have had an inflammatory bowel disease, such as Crohn disease or ulcerative colitis;
  • have previously had special types of polyps, called adenomas, in the bowel; or
  • have a significant family history of bowel cancer or polyps.

What is a significant family history of bowel cancer?

You are considered to have a significant family history of bowel cancer if a close relative (parent, brother, sister or child) developed bowel cancer at a young age (under 50 years) or if more than one relative on the same side of your family has had bowel cancer.

More than 75 per cent of people who develop bowel cancer do not have a family history of bowel cancer4.

If you think you have a family history of bowel cancer, you should talk to your doctor about your risk of getting the disease.

4 ibid, p 72.