Bowel cancer can develop quietly, but early detection and regular screening can make a major difference. Understanding your risk, knowing the warning signs and participating in Australia’s free screening programme when eligible are important steps in protecting your bowel health.
- In 2025, an estimated 14,784 Australians will be diagnosed with colorectal cancer, and an estimated 5,235 people will die from the disease.
- Bowel cancer is estimated to be the fifth most commonly diagnosed cancer in Australia in 2025 and the second leading cause of cancer death.
- Many bowel cancers begin as polyps, which can grow slowly before some become cancerous, often without early symptoms.
- Eligible Australians aged 45 to 74 can complete a free at-home bowel screening test every two years. People aged 50 to 74 are mailed a kit automatically, while people aged 45 to 49 can request their first free kit.
Why this matters in Australia
Bowel cancer, also called colorectal cancer, develops in the colon or rectum. In many cases, it starts as a small growth called a polyp on the inner lining of the bowel. Not all polyps become cancer, but some can change over time.
This is why screening matters. Bowel cancer often causes no symptoms in its early stages, so a person may feel well while changes are already developing. Screening can help detect tiny traces of blood in stool that may not be visible.
Early action can also improve treatment outcomes. The Australian Government notes that when bowel cancer is found early, more than 90% of cases can be successfully treated.
Understanding your risk factors
Some risk factors cannot be changed. Knowing about them helps you decide when and how often to be screened and whether you need a colonoscopy rather than a home test kit.
Age is the single most significant non-modifiable risk factor. Bowel cancer is more common after age 50, although younger Australians can also be affected. This is one reason proactive screening from age 45 is now encouraged.
Family history can also affect your risk. Your risk may be higher if a close relative, such as a parent, brother or sister, has had bowel cancer. The risk may be higher again if they were diagnosed at a younger age or if more than one close relative has been affected.
Genetic conditions carry the highest risk of all. These include Lynch syndrome and familial adenomatous polyposis. People with these conditions often need colonoscopy from a younger age and more regular monitoring.
Personal medical history also matters. A prior bowel cancer diagnosis raises the risk of a second primary cancer. People with inflammatory bowel disease, including Crohn’s disease and ulcerative colitis, face a two to three-fold increased risk of bowel cancer after eight to ten years of active disease.
The Australian Institute of Health and Welfare estimates that 53% of the bowel cancer burden in Australia is attributable to combined modifiable risk factors. Addressing these factors through lifestyle choices can meaningfully lower your individual risk.
Lifestyle can also influence bowel cancer risk. A diet low in fibre, high intake of red or processed meat, being above a healthy weight, alcohol use, smoking and physical inactivity are all linked with increased risk. These factors do not mean bowel cancer will happen, but improving them may help lower risk over time.
Recognising early symptoms
Bowel cancer may not cause symptoms at first. Polyps and early-stage cancers may grow silently for years before producing any noticeable change.
When symptoms do appear, they can be easy to dismiss or mistake for another bowel condition. This is precisely why screening matters even when you feel completely well. It is best to speak with your GP if symptoms persist, return or feel unusual for you.
Symptoms that should be checked include:
- Blood in the stool or rectal bleeding
- A lasting change in bowel habits, such as diarrhoea, constipation or alternating between both
- A feeling that the bowel has not emptied completely
- Ongoing abdominal pain, bloating or cramping
- Unexplained weight loss or reduced appetite
- Unexplained tiredness, weakness, breathlessness or anaemia
Cancer Council Australia lists bleeding, changes in bowel habits, abdominal pain or bloating, unexplained weight loss, loss of appetite and symptoms of anaemia as symptoms that should be discussed with a doctor.
Some symptoms require prompt medical attention, ideally on the same day or within 24 to 48 hours. These include any rectal bleeding even if it occurs only once, unexplained iron-deficiency anaemia, a palpable abdominal mass or lump, severe or rapidly worsening abdominal pain, or signs of bowel obstruction such as severe pain, vomiting, and inability to pass wind or stools. If your GP is unavailable, visit the emergency department.
Prevention you can start today
You cannot control every bowel cancer risk factor, but everyday habits can support better bowel health. The goal is to make steady, practical choices that lower risk where possible.
A bowel-friendly diet includes:
- Wholegrains such as oats, wholegrain bread, brown rice, barley and quinoa
- Legumes such as lentils, chickpeas and beans
- Plenty of vegetables and fruit
- Nuts and seeds, where suitable for your diet
- Less processed meat, including bacon, ham, salami and sausages
Other helpful steps include:
- Stay active most days, even if you start with short walks
- Limit long periods of sitting where possible
- Maintain a healthy weight
- Avoid smoking
- Reduce alcohol intake
Making lasting changes to your diet and daily routine can be difficult to manage on your own. You can always talk to us regarding a referral to our nutrition and dietetic services and hypnotherapy services for practical support with your long-term bowel health.
Regular participation in screening is genuine prevention, not just early detection. Most bowel cancers begin as adenomatous polyps that take years to develop into cancer. Screening tests can detect polyps before they become cancerous, and when polyps are identified through colonoscopy they can usually be removed during the same procedure, interrupting the pathway to cancer entirely.
Australia’s National Bowel Cancer Screening Programme (NBCSP) provides free screening to eligible Australians. Since 1 July 2024 Australians aged 50 to 74 receive a free immunochemical faecal occult blood test (iFOBT) kit every two years, posted directly to their home address. Australians aged 45 to 49 can request a free kit by calling 1800 627 701. The iFOBT detects tiny amounts of blood in stool that may indicate the presence of polyps or cancer, completed at home and returned by post at no cost. Among current participants, 44% are diagnosed at a less advanced stage compared with 24% of non-participants.
Survival rates by stage
The stage at which bowel cancer is detected has a profound impact on survival outcomes. Current Australian data reflects the following approximate five-year survival rates by stage.
| Stage | Description | Approximate 5-Year Survival |
| Stage 1 | Localised to bowel wall | ~99% |
| Stage 2 | Grown through bowel wall, no spread | ~85% |
| Stage 3 | Spread to nearby lymph nodes | ~70% |
| Stage 4 | Spread to distant organs | ~15% |
These figures show why completing a screening test, or investigating symptoms promptly, is so important. Regular participation in the NBCSP can reduce the risk of dying from bowel cancer by up to 33%. Data from the NBCSP shows that participants with screen-detected bowel cancer have a 9.6% cancer-related mortality rate, compared with 23.8% among non-participants.
Higher-risk groups who need more than standard screening
The standard NBCSP iFOBT is appropriate for average-risk individuals. Some people require more intensive surveillance through colonoscopy.
Speak with your GP or gastroenterologist about an individual screening plan if you have:
- A strong family history of bowel cancer
- A close relative diagnosed at a younger age
- Lynch syndrome or familial adenomatous polyposis
- Inflammatory bowel disease, including Crohn’s disease or ulcerative colitis
- A previous bowel cancer diagnosis
- A history of adenomatous polyps
Discuss your personal and family history with your GP to determine the most appropriate schedule. Do not assume the standard NBCSP two-yearly kit is sufficient if additional risk factors are present.
Frequently Asked Questions
What is the most common symptom of bowel cancer?
Blood in stool or rectal bleeding is the most important warning sign. However, bowel cancer often causes no symptoms in early stages, which is why regular screening matters even when you feel well.
At what age should I start bowel cancer screening in Australia?
If you are aged 50 to 74, you receive a free NBCSP screening kit every two years automatically. If you are aged 45 to 49, you can request a free kit by calling 1800 627 701. Those at higher risk due to family history may need to begin screening earlier, which should be discussed with your GP or gastroenterologist.
How much does bowel cancer screening cost in Australia?
The NBCSP iFOBT screening kit is free for eligible Australians aged 45 to 74. The reply-paid envelope for returning your samples is also included at no cost.
Can bowel cancer be prevented?
Up to 47% of bowel cancers may be preventable through lifestyle changes including increasing fibre intake, reducing red and processed meat consumption, exercising regularly, maintaining a healthy weight, limiting alcohol, and not smoking. Screening can also prevent cancer by detecting and removing polyps before they become cancerous.
What does a positive bowel screening result mean?
A positive iFOBT result means blood was detected in your stool sample. This does not necessarily mean cancer. Blood in stool can result from haemorrhoids, polyps, or other benign conditions. A positive result should be followed up with your GP promptly so a colonoscopy can be arranged.
When should I see a gastroenterologist rather than my GP?
Your GP is typically the first point of contact, and a gastroenterologist becomes involved when colonoscopy or specialist assessment is required. Reasons for referral include a positive NBCSP result, persistent or concerning symptoms such as rectal bleeding or unexplained anaemia, a strong family history of bowel cancer, or a known hereditary condition.
Sources
- Cancer Australia, Bowel Cancer Statistics, 2024
- AIHW, Bowel Cancer Burden Report, 2025
- Cancer Council Australia, Meat and Cancer Risk, 2024
- Cancer Council Australia, Wholegrains and Fibre, 2024
- Cancer Council Australia, Bowel Cancer Symptoms, 2024
- AIHW, Cancer Risk Factors, 2024
- AIHW, NBCSP Monitoring Report, 2025
- AIHW, NBCSP Performance Report, 2025
Speak to a The Centre for Gastrointestinal Health specialist
If you have concerns about your bowel health, unexplained symptoms, or a family history that may place you at higher risk, our specialist team can provide a comprehensive assessment and a personalised screening plan. The Centre for Gastrointestinal Health supports Australia’s largest network of gastroenterologists, with 12 locations across Sydney Metro and Regional NSW.
- Call 1300 580 239 to speak with our team and arrange a consultation.
- Book at your nearest of our 12 NSW locations by visiting Make an appointment for the full directory.
General educational information only. Speak to your GP or specialist about your individual circumstances.
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