When Dr. John Ding started his career as a gastroenterologist, bowel cancer was considered an old person's disease. That thinking is now being turned on its head. Australia now has the highest rate of bowel cancer among people under 50 anywhere in the world — and experts are sounding the alarm.
Bowel cancer, also called colorectal cancer, affects roughly 1 in every 20 Australians. While rates have actually dropped among people over 50 thanks to a national screening program, the opposite is happening in younger adults. The reason isn't fully understood, though Dr. Ding points to lifestyle factors like processed foods, lack of exercise, and obesity as key contributors.
The good news? When caught early, bowel cancer is highly treatable. "If you catch it early enough, you can cure it in about 99% of people," says Dr. Ding, who is both an associate professor of gastroenterology and a spokesperson for Bowel Cancer Australia. That early detection often comes through a colonoscopy, where doctors can spot and remove tumors before they spread.
The challenge is getting people screened before symptoms appear. Until 2024, Australia's free national bowel cancer screening program was only available to those 50 and older. Now, thanks to rising rates among younger adults, the program has been expanded to include people aged 45 and up. Some experts are pushing for it to start even earlier, at 40.
Dr. Ding says many younger patients are being misdiagnosed. "Often people with early-onset bowel cancer are delaying presentation. They are often misdiagnosed as having things like irritable bowel syndrome." He urges anyone with three warning signs — blood in their stool, a lasting change in bathroom habits, or unexplained stomach pain — to see a doctor right away.
Beyond screening, experts say small lifestyle changes can make a big difference. Ultra-processed foods, common in modern diets, may damage the gut microbiome — the ecosystem of helpful bacteria in our digestive system. Cutting back on these foods, exercising more, and eating more fiber could help lower risk.
Only about a quarter of early-onset cases are linked to genetic syndromes, meaning the majority are influenced by environment and lifestyle. That also means there's real room for prevention.
For Dr. Ding, the message is simple: bowel cancer doesn't care how old you are. "People of all ages can be screened," he says. "You're not too young."