Young-Onset Colorectal Cancer

Young-onset colorectal cancer refers to bowel cancer diagnosed in people under the age of 50. While bowel cancer is more common in older adults, rates of colorectal cancer in younger people have been increasing worldwide.

It is a common misconception that bowel cancer only affects older people. In Australia, approximately 1 in 8 people diagnosed with bowel cancer are under the age of 50. Younger people should never be told they are “too young” to have bowel cancer.

Because bowel cancer is often not initially suspected in younger adults, diagnosis can sometimes be delayed. Many symptoms may also be mistaken for more common benign conditions such as haemorrhoids or irritable bowel syndrome.

Symptoms

Symptoms of young-onset colorectal cancer are similar to those seen in older patients and may include:

  • Rectal bleeding

  • Change in bowel habit

  • Persistent diarrhoea or constipation

  • Abdominal pain or bloating

  • Unexplained weight loss

  • Fatigue or iron deficiency anaemia

  • A feeling of incomplete emptying after bowel motions

Most people with these symptoms will not have bowel cancer, however persistent or concerning symptoms should always be assessed by a doctor.

Risk Factors

In many young patients, there may be no obvious risk factor identified. However, factors that may increase risk include:

  • Family history of bowel cancer or polyps

  • Inherited cancer syndromes

  • Inflammatory bowel disease

  • Obesity

  • Smoking

  • Diets high in processed meats

  • Sedentary lifestyle

Some younger patients diagnosed with colorectal cancer have no family history or identifiable risk factors.

Importance of Early Recognition

Early diagnosis significantly improves outcomes. Young people should seek medical attention if symptoms persist or if something does not feel right.

No one knows your body better than you. Persistent rectal bleeding, ongoing changes in bowel habit, unexplained abdominal symptoms, or iron deficiency should not be ignored, regardless of age.

Awareness initiatives such as the Never2Young campaign by Bowel Cancer Australia aim to improve recognition of early-onset bowel cancer, support younger patients, and advocate for earlier diagnosis and improved care.