Colorectal cancer affects the colon or rectum. Symptoms can be subtle or absent in early disease, which is why screening may be recommended for eligible people even when they feel well. The appropriate age to begin screening and the best test depend on local guidelines, personal risk, family history and access to care.
Possible warning signs
Changes in bowel habits that persist, blood in the stool, unexplained weight loss, ongoing abdominal discomfort, unusual fatigue or iron-deficiency anaemia may require medical assessment. These symptoms can have causes other than cancer, but they should not be ignored or self-diagnosed.
Who may have a higher risk?
Risk can increase with age and may be higher with a family history of colorectal cancer or certain polyps, some inherited conditions, inflammatory bowel disease and other factors. A clinician can help determine whether earlier or more frequent screening is appropriate.
What does screening involve?
Depending on the setting and guidance, screening may include stool-based tests or visual examination of the colon. Each approach has benefits, limitations and follow-up requirements. A positive screening result usually needs further assessment; it does not by itself mean cancer is present.
Steps to take
- Ask your healthcare professional when screening is recommended for your age and risk profile.
- Share any family history of colorectal cancer or significant polyps.
- Seek medical advice for persistent bowel changes or blood in the stool rather than waiting for a routine screening date.
- Discuss lifestyle factors such as physical activity, diet, smoking and alcohol with your clinician.
Frequently asked questions
Is screening only for people with symptoms?
No. Screening is intended to find disease or precancerous changes in eligible people who may feel well.
Does a positive stool test confirm cancer?
No. Follow-up testing is needed to determine the cause.
Further reading: National Cancer Institute colorectal cancer screening information.
Medical disclaimer: This article is educational and does not replace a clinician’s advice or recommended screening plan.
