Can Young People Get Bowel Cancer?

The Emerging Reality

For a long time, bowel cancer was thought of as something that mostly affected older people. And it is true that the risk goes up significantly with age — more than 90% of cases are still diagnosed in people over 50. But something concerning has been happening since the 1990s: bowel cancer in people under 50 — called early-onset colorectal cancer — has been rising steadily, not just in Australia, but across the UK, US, and many other countries.

In Australia, around 1,600 to 1,800 people under 50 are diagnosed with bowel cancer every year. That is a meaningful number. What makes it especially worrying is that younger people are often diagnosed at a later, harder-to-treat stage — partly because their symptoms get put down to stress, IBS, or haemorrhoids, and the possibility of something more serious is not explored quickly enough.

Why Are Rates Rising in Young Adults?

Researchers are still working to understand exactly why, but a number of factors are thought to play a role:

• Diet: eating more processed food, red meat, and less fibre than previous generations
• Less physical activity: sitting more is linked to a higher bowel cancer risk
• Higher rates of excess weight: carrying extra weight around the middle is associated with increased bowel cancer risk
• Alcohol: even moderate drinking is associated with higher risk
• Changes in gut bacteria: modern diets and antibiotic use may be affecting the balance of bacteria in the bowel in ways that matter over a lifetime

It is worth saying clearly: many young people who are diagnosed with bowel cancer have none of these risk factors. Being active, eating well, and being a healthy weight does not make you immune. This disease does not only affect people with "unhealthy" lifestyles.

Symptoms Young People Commonly Dismiss

One of the biggest issues with bowel cancer in younger people is how long it takes for them to get properly investigated. Research shows that young adults with bowel cancer often wait much longer to see a doctor than older people do — and that doctors can also be slower to investigate when a patient is young. It is understandable. These symptoms almost always turn out to be something benign. But that is also what makes them easy to put off.

The symptoms that are most commonly explained away include:

• Bleeding from the back passage: almost always put down to haemorrhoids (piles), especially in younger people who strain, sit for long periods, or have noticed haemorrhoids before
• Change in bowel habits: put down to diet, stress, travel, or IBS (irritable bowel syndrome — a common condition affecting the gut)
• Abdominal cramping: often attributed to IBS, period pain, or food intolerance
• Persistent tiredness: blamed on a busy life, stress, or not sleeping enough
• Tenesmus — the feeling that your bowel has not fully emptied: often put down to IBS or anxiety

All of these symptoms genuinely do have common, non-serious explanations most of the time. That is exactly why it is so easy to reassure yourself they are nothing. The issue is that these same symptoms can also be the first sign of bowel cancer — and the only way to tell the difference is to get properly assessed.

If You Are Under 50 — Do Not Dismiss These Symptoms

Family History in Young People

If a close family member — a parent, sibling, or child — has been diagnosed with bowel cancer, your own risk is higher than average. The good news is that there are clear guidelines about what to do. Australian guidelines recommend starting colonoscopy screening from age 40 to 45 (or 10 years before the age your relative was diagnosed, whichever is earlier) for people with one close relative affected. For hereditary conditions like Lynch syndrome or FAP (familial adenomatous polyposis — a condition that causes many polyps to grow in the bowel), screening should begin much earlier, sometimes in your mid-twenties.

If you are in your twenties or thirties and someone in your immediate family has had bowel cancer — especially if they were young when they were diagnosed — please speak to your GP now about your options. You do not have to wait until 45.

What Happens When a Young Person Is Investigated

If you see your GP with concerning bowel symptoms, they will take a full history and examine you, which may include a gentle examination of your lower bowel. Blood tests — including a full blood count to check whether you are anaemic (low in iron) — may also be organised.

If your symptoms are persistent or there are any features that need further investigation, the next step is usually a referral to a colorectal surgeon for a colonoscopy. A colonoscopy — performed under light sedation so you are comfortable and have no memory of it — allows the surgeon to look directly at the entire bowel lining, take small tissue samples if needed, and remove any polyps found at the time. It is generally well tolerated and much less daunting than people expect.

If your colonoscopy comes back completely normal, that is genuinely good news. It rules out bowel cancer as the cause of your symptoms, and your doctor can then focus on managing whatever is actually responsible. Peace of mind has real value too.

Reducing Risk at Any Age

Bowel cancer cannot always be prevented, but there are real things you can do to lower your risk. None of these are dramatic changes — they are the same sensible habits that protect your health in general:

Frequently Asked Questions