Australia has long prided itself on its world-class healthcare system and sun-soaked lifestyle, but a worrying trend has left experts scratching their heads.
Despite overall improvements in cancer detection and treatment, Australia now records some of the highest rates of aggressive bowel cancer in the world. And the most unsettling part? No one knows why.
For decades, bowel cancer—also known as colorectal cancer—was considered a disease of older age. But the statistics are shifting.
Over the past 30 years, more than 28,000 Australians under 50 have been diagnosed with bowel cancer, with an estimated 4,300 additional early-onset cases compared to what would have been expected.
Professor Mark Jenkins, head of the colorectal cancer unit at the University of Melbourne, has been at the forefront of tracking this trend.
‘It’s getting worse—in Australia, but also around the world—it’s increasing,’ he said. ‘So there’s something going on, but we don’t know why.’
Bowel cancer develops in the lining of the colon or rectum, often without noticeable symptoms in its early stages. This makes it a particularly insidious disease, as it can spread rapidly before being detected.
The statistics are sobering, but the human stories behind them are even more so. Take Laura Corfield, a Brisbane mum who was just 35 when she received her diagnosis.
Corfield’s journey began with what she thought were typical pregnancy symptoms: persistent tummy pain and nausea.
Doctors initially reassured her, but Corfield knew something wasn’t right as the discomfort lingered. At 22 weeks pregnant, she was diagnosed with Stage 3 bowel cancer—aggressive and advanced.
‘I was in total disbelief,’ she shared. ‘They used all those words you don’t want to hear at that moment.’
Corfield’s story is, unfortunately, not unique. More young Australians are facing similar diagnoses, often at a stage when the cancer is already advanced.
What’s behind the rise?
So, what’s driving this surge in aggressive bowel cancer among younger Australians? The short answer: we don’t know for sure. But there are several theories.
Rising rates of obesity, declining physical activity, and changes in diet are all under the microscope. The modern Australian lifestyle, with its processed foods and sedentary habits, may contribute to the problem.
There’s also evidence that regular use of certain medications, like aspirin, can reduce bowel cancer risk. A decline in their use could be a factor.
One of the more recent suspects is microplastics—tiny plastic particles in our food and water.
Dr Michelle Blewitt, a leading microplastics researcher, explained: ‘Every time Aussies wash their clothes, millions of tiny microfibres are shed and released. When these plastics make their way into our oceans, they’re often eaten by fish and aquatic life, and subsequently by us.’
‘Anything less than five millilitres in size is a microplastic, and if it gets smaller than one millilitre, it becomes nanoplastics, and then picoplastics, until we’re breathing it in.’
Perhaps the most compelling theory involves the gut microbiome—the trillions of bacteria in our digestive tract.
‘Maybe there’s been a change in them, maybe they’ve become more toxic over time,’ said Jenkins.
Changes in gut bacteria, possibly driven by diet, antibiotics, or environmental factors, could be involved.
Despite these theories, none fully explain the dramatic rise in early-onset bowel cancer. Researchers are now turning to molecular studies, analysing tumour DNA to find answers.
While the causes remain elusive, one thing is clear: early detection saves lives. Australia’s national bowel cancer screening program is one of the best in the world, and it’s now available to people aged 45–49, who can request a free home test kit online.
Jenkins urged everyone in this age group to take advantage of the program.
But what about those under 45? If you have a strong family history of bowel cancer, don’t wait—talk to your doctor about whether you should be screened earlier.
Symptoms to watch for
Bowel cancer can be a master of disguise, with symptoms that are easy to dismiss or attribute to other causes. Here’s what to look out for:
- Blood in your stool
- Persistent changes in bowel habits (diarrhoea, constipation, or narrowing of the stool)
- Unexplained weight loss
- Ongoing fatigue
- Abdominal pain or discomfort
While many things can cause these symptoms, if you notice them, especially in combination, it’s worth getting checked out.
Bowel cancer is one of the most treatable cancers if caught early, but once it spreads, it becomes much harder to manage. That’s why awareness, vigilance, and early action are so important.
Have you or someone you know been affected by bowel cancer? Do you have questions or concerns about screening or symptoms? We’d love to hear your stories, thoughts, and tips in the comments below.
Also read: Popular over-the-counter drug linked to cancer—should you stop taking it?
I was diagnosed with bowel cancer at 52 years old. My GP insisted I have a CT Scan. It was negative. She then insisted I get a colonoscopy and the tumour was detected, stage 3 cancer. An operation and 6 months of chemo. Then three years later I had a CT scan and chest X-ray. Then a pet scan, tumours detected in my lung and in my liver. Metasticies. Two more ops and another 6 months of chemo. 25 years later I’m cancer free. On one occaision I mentioned to a nurse that I was not looking forward to a scan result. She replied “Peter, never put your head in the sand”. Do the test, it could save your life.