Colorectal Cancer
Colorectal cancer, also called bowel cancer, begins when cells in the colon or rectum grow abnormally and form a tumour. It is common but highly treatable when found early, and screening can detect it, or even prevent it, before symptoms appear.
Overview
What is colorectal cancer?
Colorectal cancer is a cancer that starts in the large bowel, which includes the colon and the rectum. It often begins as a small non-cancerous growth called a polyp, which can slowly turn into cancer over time. Because this process is usually gradual, screening can find and remove polyps early, helping to prevent cancer from developing.
How common is colorectal cancer / who does it affect?
Colorectal cancer is one of the most common cancers worldwide and affects both men and women. The risk increases with age, so it is most often diagnosed in older adults, although it can occur earlier. A family history or certain bowel conditions can also raise the chance of developing it. When found early, the outlook is generally very good.
Symptoms and Causes
What are the symptoms of colorectal cancer?
Common symptoms include a lasting change in bowel habits, such as looser stools or going more often, blood in the stool or bleeding from the back passage, and tummy pain or bloating. Some people feel unusually tired, lose weight without trying, or feel that the bowel has not fully emptied. These signs have many causes, but persistent ones should be checked.
What causes colorectal cancer and who is at risk?
The exact cause is not always clear, but risk is linked to age, a family history, and inherited conditions affecting the bowel. Lifestyle factors such as a diet high in red or processed meat, low fibre intake, being overweight, smoking, and regular alcohol use can also play a part. Long-standing inflammatory bowel disease may raise risk too.
Diagnosis and Tests
How is colorectal cancer diagnosed?
Diagnosis often begins with a stool test to check for hidden blood and a physical examination. The main test is a colonoscopy, where a thin flexible camera examines the inside of the bowel and can remove tissue samples or polyps for testing. If cancer is found, scans such as CT or MRI may be used to see whether it has spread and to plan treatment.
Management and Treatment
How is colorectal cancer treated or managed?
Treatment depends on where the cancer is, its stage, and your overall health. Surgery to remove the affected part of the bowel is the main treatment for many people. Chemotherapy, radiotherapy, and targeted drug therapies may also be used, sometimes before or after surgery. A specialist team will design a plan suited to your needs, often with the aim of cure.
Prevention
Can colorectal cancer be prevented or detected early?
Bowel cancer screening is one of the best tools for early detection and can even prevent cancer by finding and removing polyps. Taking part when invited is strongly encouraged. A healthy lifestyle also helps: eating plenty of fibre, limiting red and processed meat and alcohol, staying active, not smoking, and keeping a healthy weight all lower your risk.
Additional Common Questions
What is a polyp and does it always become cancer?
A polyp is a small growth on the bowel lining. Most polyps are harmless, but some can slowly turn into cancer over years, which is why removing them during screening is helpful.
Is blood in the stool always a sign of cancer?
No. Bleeding is often caused by less serious conditions such as piles. Still, blood in the stool should always be checked by a doctor so the cause can be found.
At what age should I think about bowel screening?
Screening is usually offered from a certain age that varies by country. If you have a family history or symptoms, speak to your doctor, who may recommend starting earlier.
This health topic is for general information and is not a substitute for professional medical advice. Always consult a qualified clinician about your individual situation. See our medical disclaimer.