Bowel cancer in younger adults and the symptoms to know

GastroLife · 5 October 2026

Three younger adults beside an abstract blue digestive health motif — Illustration for bowel health awareness in younger adults.

Bowel cancer can affect younger adults, even though it remains much more common in older people. Rates in under-50s are rising in many countries, and a major new UK study is investigating why. For younger readers, the practical message is to know the symptoms and seek medical advice about changes, rather than assuming age rules out a serious problem. ^{[1, 2]}

What the new study is investigating

On 5 October 2026, Sky News reported that researchers are seeking 250,000 people for PROSPECT-UK. Led by King’s College London and ZOE, the study will explore how diet, lifestyle, gut health and environmental exposures may influence bowel cancer risk. ^{[1, 2]}

Participants will complete questionnaires and be asked to consent to linking their information with electronic health records. A smaller group will provide detailed food diaries and blood and stool samples. Following people over time may help researchers identify patterns associated with the disease. This is research into possible causes; it has not yet established what is driving the increase. ^[2]

King’s College London describes recruitment as open to adults over 18 living in the UK. Readers in the Republic of Ireland should note that this is a UK study and check the official study website for current eligibility. ^[2]

What rising rates mean for younger people

Bowel cancer diagnosed before age 50 is often called early-onset colorectal cancer. Cancer Research UK reported that an international analysis found rising rates in younger adults in 27 of the 50 countries and territories studied, using data up to 2017. ^[3]

That finding does not mean bowel cancer is common in young adults or that the same increase applies in every country. It does mean that being younger should not be a reason to overlook symptoms. Researchers are still investigating the reasons for the trend, including possible dietary, environmental and biological influences. ^{[2, 3]}

A younger woman noting abdominal symptoms in a notebook at home — Notice changes in your usual bowel habits and discuss symptoms with your GP.

Symptoms that deserve medical attention

Contact your GP if you notice symptoms such as: ^[4]

Blood in your stool or bleeding from your bottom.
A change in your usual bowel habits, including diarrhoea, constipation or going more or less often.
Unexplained abdominal pain, bloating or a lump in your abdomen.
Unexplained weight loss.
Unusual tiredness or breathlessness.

These symptoms can have causes other than cancer, but they should be checked. The HSE advises contacting your GP even after a recent normal bowel screening result. Do not wait for a screening invitation or your next screening test if you have symptoms. ^[4]

Family history and personal risk

Tell your GP if a close relative has had bowel cancer, particularly at a young age, or if your family has an inherited condition such as Lynch syndrome or familial adenomatous polyposis. This may change the assessment or monitoring you need. Having no known family history does not eliminate the possibility of bowel cancer. ^[5]

A hand holding a sealed return envelope beside a green Irish postbox — Returning a sealed home-testing package by post. Follow the return instructions supplied with your kit.

Where FIT testing fits in

A faecal immunochemical test, or FIT, checks a stool sample for small amounts of blood that may be invisible. It is used in bowel screening and can also help clinicians investigate certain bowel symptoms. ^{[6, 7]}

A positive FIT result does not diagnose cancer: blood may have other causes. A negative result does not completely rule out bowel cancer. If symptoms continue or there is clinical concern, further assessment may still be needed, including consideration of colonoscopy. Your GP should guide the next steps. ^{[6, 7]}

Ireland’s BowelScreen programme currently covers people aged 57 to 71 who have no bowel cancer symptoms. Being outside that age range does not prevent you from seeking medical assessment. Screening eligibility and the investigation of symptoms are different matters. ^[8]

Reducing risk while research continues

The Irish Cancer Society recommends eating more fibre, limiting red and processed meat, keeping physically active, maintaining a healthy weight, avoiding smoking and reducing or avoiding alcohol. These measures can help reduce bowel cancer risk, but they do not guarantee prevention or explain every case in a younger person. ^[5]

GastroLife home FIT testing

GastroLife offers home FIT testing to check for hidden blood in stool. We provide testing only; your GP or consultant should consider your result alongside your symptoms and medical history. If you have symptoms, contact your GP promptly and ask whether FIT is appropriate. Do not delay medical assessment while arranging a home test or waiting for its result. ^{[4, 9]}

For information about our home FIT test, visit gastrolife.ie or contact info@gastrolife.ie. ^[9]

Learn more about GastroLife’s home FIT test.

View home FIT testing

Information provided is for educational use only and should not replace professional medical advice or diagnosis.

References

Sources checked on 5 October 2026.