Bowel cancer

Last updated 13 February 2017 — Last reviewed 15 January 2014

Bowel cancer is a common cause of cancer related death in Australia, yet it is not talked about as much as other cancers. What is bowel cancer, the symptoms of bowel cancer, who is at risk and how to be screened?

What is bowel cancer?

Bowel cancer, also known as colorectal cancer, is a malignant growth inside the lining of the large bowel. The colon and rectum make up the large intestine. Most bowel cancers start out as polyps, which look like small spots on the bowel lining or like cherries on stalks, protruding from the wall of the bowel.

Colon polyps

Australians have a high incidence of bowel cancer. "One person dies on our roads every six hours, one person dies of breast cancer every four hours, but one person dies from bowel cancer every two hours," says gastroenterologist Dr David Devonshire, from Monash Health. According to David, screening with a stool (poo) test for small amounts of blood has been shown to reduce bowel cancer death rates by 30%. A colonoscopy test (under sedation a long, thin tube is inserted up the rectum to look for polyps) may reduce the rate by 70% or more, thus potentially preventing thousands of deaths each year.

Symptoms of bowel cancer

The most common symptoms of bowel cancer are:

  • blood or mucus in the stool
  • unexplained change in bowel habits (e.g. diarrhoea, constipation, incomplete emptying of the bowel)
  • discomfort in the stomach (such as pain, cramps, bloating, fullness)
  • thinner than usual bowel motions
  • unexplained weight loss
  • fatigue and weakness

If you experience these symptoms, see your doctor.

Who is at risk?

The exact cause of bowel cancer is unknown. However, certain factors increase your risk so if you fall into any of these categories, see your doctor for advice about bowel cancer screening.

Ageing Bowel cancer commonly affects people over the age of 50.
Family history Although 75% of people who develop bowel cancer have no family history, you are at increased risk of developing bowel cancer if any family members have a history of bowel cancer at a young age, especially close relatives such as parents, siblings or children.
Genetic factors

Some genetic conditions increase your chance of developing bowel cancer such as:

  • familial adenomatous polyposis (FAP) and
  • hereditary non-polyposis colorectal cancer (HNPCC – lynch syndrome) 

Cancer of the:

  • colon
  • rectum
  • endometrium
  • ovary
  • breast
People who have, or have had, these conditions are at greater risk of developing bowel cancer.

Other disorders related to bowel cancer include ulcerative colitis, crohn's disease and polyps.

Bowel cancer screening

90% of bowel cancers are treatable if caught early.

Unfortunately, most bowel cancers show no symptoms in the early stages so many people do not realise that something is wrong until it's too late.

The National Bowel Cancer Screening Program offers free screening tests to all Australians aged 50, 55 or 65. This test involves collecting tiny samples from two bowel motions using a home testing kit. The samples are then posted to a laboratory where a faecal occult blood test (FOBT) is used to detect microscopic amounts of blood that might indicate early stage bowel cancer.

Management & treatment

Treatment depends on the stage of the bowel cancer and may include surgery, chemotherapy and/or radiation. Management and treatment of bowel cancer is best discussed with your doctor.

This web page is designed to be informative and educational. It is not intended to provide specific medical advice or replace advice from your health practitioner. The information above is based on current medical knowledge, evidence and practice as at January 2014.

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