Colorectal Cancer
Sources consulted
This article is original patient-education content.
- WHO—Health topics A–Z(2024)
- NHS—Health A to Z(2024)
- CDC—Health topics(2024)
Based on international clinical guidelines
Overview
Colorectal cancer is a disease where abnormal cells grow in the colon or rectum (parts of the large intestine). It is also called bowel cancer. These cells can form a growth called a tumour and may spread to other parts of the body if not found early.
Key facts
- Colorectal cancer is one of the most common cancers in the UK and worldwide.
- It often starts as small growths called polyps, which can be removed before they turn into cancer.
- Screening can find it early, when treatment is more likely to work.
Yes, colorectal cancer is common. In the UK, it is the fourth most common cancer in adults.
It mainly affects people over 50, but younger adults can also get it. It affects men and women, though slightly more men.
Symptoms
- Severe abdominal pain that comes on suddenly
- Vomiting blood or passing large amounts of blood from the bottom
- Feeling very faint or collapsing
- ⚠New or worsening blood in your stool that doesn't go away after a day or two
- ⚠A sudden change in bowel habit that lasts more than three weeks
- ⚠Unexplained weight loss or extreme tiredness
Common symptoms
- A persistent change in bowel habits (like diarrhoea, constipation, or feeling you haven't emptied your bowel fully)
- Blood in your stool (poo) — this can be bright red or dark
- Unexplained weight loss
- A feeling of a lump in your tummy or back passage
- Extreme tiredness for no clear reason
Symptoms in children
- Colorectal cancer is extremely rare in children. If a child has symptoms like persistent stomach pain, changes in bowel habits, or blood in the stool, see a doctor — but it is most often caused by other conditions.
Symptoms in older adults
- Older adults may have the same symptoms as younger people. Sometimes they dismiss bleeding or bowel changes as 'just getting older', but any persistent change should be checked by a doctor.
Causes
Main causes
- The exact cause is not known, but it starts when healthy cells in the colon or rectum develop changes (mutations) in their DNA. These mutations cause cells to grow out of control.
Risk factors
- Getting older (most cases are in people over 50)
- A personal or family history of bowel polyps or colorectal cancer
- Inflammatory bowel disease (like Crohn's disease or ulcerative colitis)
- A diet high in processed meats and low in fibre
- Being overweight or not physically active
- Smoking and drinking a lot of alcohol
When to see a doctor
See a doctor urgently if:
- If you have blood in your stool or a lasting change in bowel habits that is new and worrying
- If you have severe stomach pain that doesn't go away
Book a routine appointment if:
- If you have mild digestive symptoms that last more than a few weeks, even if they are not urgent
- If you are eligible for bowel cancer screening (usually from age 50-60 in the UK), make sure you take the test
Diagnosis
Your doctor will ask about your symptoms and family history. They may examine your tummy and do a simple test on a stool sample to look for hidden blood. If needed, they will refer you to a specialist for further tests.
Tests that may be done
- Stool test (Faecal Immunochemical Test or FIT) to check for blood
- A colonoscopy (a thin, flexible tube with a camera inside your bowel)
- A CT scan or other imaging to see if cancer has spread
What to expect at your appointment
If you need a colonoscopy, you will be given instructions to clean your bowel beforehand. The test itself is usually done while you are sedated, so you feel relaxed. It takes about 30 minutes. You may have mild discomfort but it is well tolerated.
Treatment
Treatment for colorectal cancer depends on the stage (how far it has spread) and your overall health. It often involves a combination of surgery, radiotherapy, and drug treatments. Your healthcare team will create a plan tailored to you.
Self-care at home
- Eating a well-balanced diet and staying as active as you can during treatment
- Getting plenty of rest and managing stress
- Stopping smoking and limiting alcohol
Medical treatments
Medical treatments include chemotherapy (drugs that kill cancer cells), radiotherapy (high-energy rays that shrink tumours), and targeted therapies that attack specific parts of cancer cells. These are given under the care of a specialist team. Some people also have immunotherapy to help their immune system fight the cancer.
When is surgery considered?
Surgery is often the main treatment for early-stage colorectal cancer. It involves removing the part of the colon or rectum containing the tumour, along with nearby lymph nodes. The surgeon may reconnect the healthy ends of the bowel. In some cases, a temporary or permanent stoma (a small opening in the abdomen where waste leaves the body) is needed.
Living with this condition
Living with colorectal cancer means attending regular check-ups and managing any side effects from treatment. Many people continue with their normal activities as much as possible. It helps to have a support network of family, friends, and healthcare professionals.
Lifestyle tips
- Stay physically active if you can — even gentle walking can help
- Eat plenty of fruits, vegetables, and whole grains
- Get enough sleep and listen to your body
- Avoid smoking and limit alcohol
Diet and exercise
A healthy diet can help you feel better during and after treatment. Choose high-fibre foods like oats, beans, and vegetables, but if you have a stoma or after surgery, your doctor may advise you to adjust fibre intake. Gentle exercise like walking or swimming can improve your energy and mood. Always check with your doctor before starting a new activity.
Mental health and emotional wellbeing
A cancer diagnosis can bring fear, anxiety, and sadness. It is normal to feel overwhelmed. Talking to a counsellor or joining a support group can help. Do not hesitate to ask for help from your healthcare team.
Prevention
There is no sure way to prevent colorectal cancer, but you can lower your risk. Getting screened regularly, staying a healthy weight, eating a diet rich in fibre, limiting red and processed meat, and not smoking all help.
Screening programmes
Screening is the best way to find polyps early or detect cancer before symptoms start. In the UK, everyone aged 50-74 is offered a bowel cancer screening home test kit every two years. If you are at higher risk due to family history, you may be offered a colonoscopy earlier.
Complications
If left untreated
- The cancer can grow and block the bowel (bowel obstruction), causing severe pain and vomiting
- Cancer can spread to other organs like the liver or lungs, making it harder to treat
- Severe bleeding from the tumour can cause anaemia (low blood count)
Long-term outlook
When found early, colorectal cancer can often be cured. Even if it is found at a later stage, treatments are better than ever, and many people live well for years. Your outlook depends on the stage, your general health, and how your cancer responds to treatment. Your doctor will give you a more personal picture.
Find support
International organisations
Local organisations
- NHS – Bowel Cancer ↗ · UK
- Cancer Council Australia ↗ · Australia
- Canadian Cancer Society ↗ · Canada
Helplines
External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.
Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.