Skip to main content

Prevention & Diagnosis

Australia has one of the highest rates of bowel cancer in the world. Yet it is also one of the most preventable cancers.

Australia has one of the highest rates of bowel cancer in the world. Yet it is also one of the most preventable cancers.

Reducing known lifestyle risk factors and undergoing regular bowel screening are vital tools in reducing the risk of developing bowel cancer.

8 ways to help prevent bowel cancer

  1. Getting screened

Screening before symptoms become present is important because bowel cancer can develop without any early warning signs. Surveillance may mean regular faecal occult blood testing (or FOBT) of the bowel movement for invisible blood. If positive for blood, a colonoscopy is recommended to investigate the cause.

Most bowel cancers develop slowly from pre-cancerous growths called polyps. Early detection and removal of these polyps prevent the development of bowel cancer.

Screening every 1 to 2  years can reduce your risk of dying from bowel cancer by up to 33%.

  1. Eat a healthy high-fibre diet

Eat a variety of fruit and vegetables, reducing saturated fats (in animal products, processed foods and takeaway). There is also strong evidence that eating fibre can help prevent bowel cancer by reducing the risk of problems such as constipation and inflammation of the bowel wall. National guidelines recommend 2 serves of fruits, 5 serves of vegetables, and wholegrain foods every day.

  1. Engage in regular physical activity

There is strong evidence that exercise cuts the risk or bowel cancer and polyps, and a sedentary lifestyle increases it. Get at least 30 minutes of moderate to vigorous activity, five or more days a week.

  1. Reduce consumption of red and processed meat

Research has shown a moderate effect of red meat in increasing the risk of bowel cancer, especially with processed meat. Charring of meat is best avoided.

  1. Don’t smoke

Smokers are more likely than non-smokers to develop bowel cancer, and even more likely to die from the disease.

  1. Maintain a healthy body weight

Obesity is linked to bowel cancer, especially in men. And the evidence points to abdominal obesity (or belly fat) as a key factor. Maintaining healthy body weight, for both men and women, also reduces the risk of a number of other diseases, including heart disease and diabetes.

  1. Drink alcohol in moderation

Heavy drinking may increase the risk of bowel cancer. If you do drink, one standard drink per day for women, two standard drinks per day for men, with 2 alcohol-free days per week for both, is recommended.

  1. Know your family history

Heredity (the genetic transmission of characteristics from parent to offspring) plays a big role in bowel cancer; up to 20% of people who develop bowel cancer have a relative with the disease. Find out if your relatives had bowel cancer or polyps that can be precursors of the disease. Also, find out how old they were when they were diagnosed. If there is a strong family history of bowel cancer in your family, genetic counselling can be beneficial.


Screening is the testing of people to detect disease early before there are any obvious symptoms. Research shows that early screening for bowel cancer does help reduce death rates. Screening saves lives!

The aim of bowel screening is to find polyps in people who have no symptoms and is important because bowel cancer can develop without any early warning signs. Detected early, 90% of bowel cancers can be treated successfully. Currently in Australia, fewer than 40% of bowel cancers are caught in the early stages.

Medical guidelines in Australia recommend that people 50 years and over with no family history of bowel cancer and no symptoms should be screened for bowel cancer every 1 to 2 years.

The most commonly used screening tools that help to identify whether bowel cancer is present include:

Faecal occult blood test (FOBT)

Immunochemical FOBT is considered the ‘gold standard for bowel cancer screening.  It is simple, non-invasive testing that can be done in the privacy of your own home. It is used to detect hidden blood in the bowel motion (or stool) often released by polyps or bowel cancers.  Screening with these tests can reduce your chance of dying from bowel cancer by up to 33%.

The completed test is returned to the pathology service by mail, and the results are sent confidentially to you and your nominated doctor. A positive result does not always mean there is cancer present, but the cause of bleeding should be investigated by colonoscopy.

The immunochemical FOBT requires no faecal handling, no change in diet or medications and has no side-effects.

Screening with an immunochemical FOBT is recommended for Australians every 1 to 2 years for those:

  • Aged 50 and over
  • With no symptoms
  • With no family history of bowel cancer or polyps

What do my FOBT results mean?

  • A negative result means that no blood has been detected in the samples provided. This does not mean that you do not have or won’t develop bowel cancer in the future, so it’s important to repeat the test every 1 to 2 years.
  • A positive result means blood has been detected in your sample. About one in 14 people will have a positive FOBT result. Bleeding can be caused by a number of conditions including polyps, haemorrhoids or inflammation, and may not necessarily be related to cancer. However, if blood is detected, further investigation with a colonoscopy is needed to find the cause.


A colonoscopy is a comprehensive and invasive procedure that allows a doctor to examine the entire length (rectum and colon) and lining of the bowel.

Prior to the colonoscopy, bowel preparation is required to clean the bowel. This is a drink taken on the day before the procedure which will empty the bowel so that it can be seen clearly. An enema may also be required (see ‘Sigmoidoscopy’).

A long, flexible and lighted tube (colonoscope) is inserted into the anus, and then pushed gently up into the rectum and colon. If polyps or anything unusual is found during the procedure, they will be removed for further examination under a microscope. This is called a biopsy.  Patients are usually given a sedative to make them feel relaxed or sleepy during the procedure, which takes 15-20 minutes.

There may be some discomfort but rarely pain. The most common side effect of a colonoscopy is temporary wind pain and flatulence – caused by the air pumped into the bowel during the procedure. More serious, but rarer, complications may include tearing the lining of the bowel or bleeding. These risks will be discussed with the patient by the doctor.

Discuss these screening options with your GP to make a decision on the best screening strategy for you based on your own medical history.

Strong family history or other risk factors?

If you have identified risk factors for polyps or bowel cancer, you may need to start screening at an earlier age. Speak to your GP to discuss the benefits of increased or earlier bowel screening based on your own circumstances.

No screening test is 100% accurate so it is important to be screened regularly. If you are worried that you might have symptoms of bowel cancer you should see your GP so the cause can be found and treated, even if you have recently had a bowel screening test.


There are a number of tests available, which are used to identify and diagnose bowel cancer.  Your GP will determine the best method of testing for you based on any symptoms you may have and your family medical history, and make any necessary referrals to other medical specialists. These tests include:

  • Rectal Examination

A simple test where the doctor inserts a gloved finger into the bottom (anus) to feel for anything unusual in the lower part of the bowel.

  • Sigmoidoscopy

This test involves a rigid or flexible lighted telescope (sigmoidoscope) being inserted into the anus to examine the last few inches of the lining of the large bowel.

  • Colonoscopy

An examination using a flexible telescope passed into the bowel through the rectum, which enables the lining of the large bowel to be examined. Unlike x-rays, which take photographs, colonoscopy allows direct visual examination of the interior of the bowel and, in most instances, can provide substantially more detail and accuracy than an x-ray. Sometimes biopsies are taken from the lining of the bowel so that they can be examined under a microscope to determine if there is any abnormality or pathology. In addition, if early polyps are present in the bowel, they will usually be removed at the time of the colonoscopy.

  • Faecal Occult Blood Test (FOBT)

Not a diagnostic test, but used to detect the presence of hidden blood in the faeces (bowel motion or stool), which may be an indication of a polyp or cancer. Clinical trials have shown that population screening for bowel cancer using FOBT does reduce deaths from bowel cancer and these tests are considered the ‘gold standard for bowel cancer screening.

  • Virtual Colonoscopy

A newer screening tool currently undergoing evaluation for accuracy and efficacy. The colon is inflated with air and a CT scanner image is taken. Virtual reality techniques construct a 3-dimensional image. If a polyp or growth is detected, a colonoscopy will be required to remove them. 

  • Barium Enema

A diagnostic test is where a small tube is inserted into the rectum and a liquid called barium is delivered. With air added, the barium is forced into the creases of the bowel wall and allows the bowel lining to be seen clearly when x-rays are taken. This method is less accurate than a colonoscopy.

Staging bowel cancer

Once a diagnosis of bowel cancer has been made, further tests such as MRI, CT and ERUS scans help to show if cancer has spread to other parts of the body. This is called ‘staging’. Staging helps the specialists work out the best treatment options.

In Australia, the most commonly used bowel cancer staging system is the Australian Clinico-Pathological Staging (ACPS) system.

Order a Screening Test

Regular screening for bowel cancer is one of the most effective ways for preventing bowel cancer. 90% of bowel cancers can be treated successfully if detected early. Screening programs are important and do save lives.

Positive results from bowel screening programs do not confirm the presence of bowel cancer but indicate the presence of blood that may be invisible to the naked eye in your bowel movement.  This may be an early warning sign.  You should speak to your GP who will initiate further investigation such as a colonoscopy.