About bowel cancer

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

Page last updated: 24 April 2019

Australia has one of the highest rates of bowel cancer in the world. It is one of Australia’s most common cancers, especially for people over 50. Around 17,000 people are diagnosed with bowel cancer each year but when detected early 90% of cases can be successfully treated.

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
  • Are overweight
  • Have a poor diet, such as a diet high in red meats, processed meats (e.g. bacon, sausages), fried foods, alcohol, or low in vegetables, fruit and whole grains (e.g. wholemeal bread, brown rice)
  • Have had an inflammatory bowel disease such as Crohn’s disease or ulcerative colitis
  • Have previously had non-cancerous tumours in the bowel
  • Have a strong family history of bowel cancer or polyps

You are considered to have a strong family history of bowel cancer if a close relative (parent, brother, sister or child) developed bowel cancer at a young age (under 55 years), if more than one close relative in your family has had bowel cancer at any age, or if one close relative and at least two second-degree relatives (grandparent, aunty, uncle, niece or nephew) had bowel cancer at any age.

More than 80 per cent of people who develop bowel cancer do not have a family history of bowel cancer.

If you think you have a strong family history of bowel cancer, talk to your doctor about your risk of getting the disease and what testing is right for you.

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.

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