About bowel cancer

Bowel cancer is one of Australia’s most common cancers, especially for people aged over 50.

Page last updated: 12 May 2015

In Australia, the lifetime risk of developing bowel cancer before the age of 75 is around one in 19 for men and one in 28 for women, which is one of the highest rates of bowel cancer in the world.

Around 80 Australians die each week from bowel cancer, but if found early it is one of the most curable types of cancer.

Bowel cancer develops when cells in the bowel lining grow too quickly, forming a clump known as a polyp or an adenoma.

Polyps are usually benign, but most bowel cancers develop from these tiny growths. Polyps can grow for several years before undergoing additional changes and becoming cancerous and spreading to other parts of the body. 


Beginnings of bowel cancer. Diagram illustrates normal cells, abnormal cells, abnormal cells multiplying, a polyp and finally bowel cancer.

Bowel cancer risk factors

There are many different risk factors for bowel cancer. The risk is greater for people who:

  • are 50 and over
  • have a significant family history of bowel cancer or polyps
  • have had an inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
  • have previously had adenomas, a type of polyp, in the bowel.

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 55 years) or if more than one relative on the same side of your family has had bowel cancer. Your doctor can work out your risk and the best screening or other testing for you based on your individual circumstances.

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

You can lower your risk of developing bowel cancer by having a healthy diet, exercising regularly, reducing your alcohol consumption and quitting smoking. More information can be found on the Cancer Council website.

More information about maintaining a healthy diet can be found on the Eat For Health Website.

Symptoms of bowel cancer

Bowel cancer can develop with few, if any, early warning symptoms. Symptoms of bowel cancer include:

  • bleeding from the rectum (back passage), or any sign of blood after a bowel motion
  • a recent and persistent change in bowel habit, for example looser bowel motions, severe constipation and/or needing to go to the toilet more than usual
  • unexplained tiredness (a symptom of anaemia)
  • abdominal pain.

If you have symptoms you should see your doctor.

Treating bowel cancer

You will usually require surgery if bowel cancer is found. If the cancer is found at an early stage, the chance of a full recovery is high. Most people will be able to return to their current lifestyle and activities.


In this section