Quick answer

What is bowel cancer?

Bowel cancer is cancer of the colon or rectum — one of the most common cancers in the UK. Symptoms include persistent change in bowel habit, blood in poo, unexplained weight loss and abdominal pain. The NHS sends screening tests to eligible adults to find cancer early. See a GP for any symptoms — do not wait for screening age.

Bowel cancer is common but often curable when found early

Bowel cancer — also called colorectal cancer — develops in the colon (large bowel) or rectum. It is one of the most common cancers in the UK, but screening and early diagnosis mean many people are treated successfully. Symptoms can be subtle or mistaken for common conditions like piles — which is why persistent symptoms and screening both matter.

Symptoms to know

Bowel cancer may cause:

  • Change in bowel habit lasting 3 weeks or more — looser stools, going more often, or alternating constipation and diarrhoea
  • Blood in poo — often without pain; may be bright red or darker
  • Unexplained weight loss
  • Persistent abdominal pain, bloating or discomfort
  • Extreme tiredness — sometimes the only sign, from iron deficiency anaemia
  • Feeling that the bowel does not fully empty after going to the toilet

Early bowel cancer may cause no symptoms at all — another reason screening is important.

Do not assume it is piles

Haemorrhoids (piles) are a common cause of rectal bleeding — but bowel cancer can cause identical symptoms. A GP should assess any unexplained bleeding or change in bowel habit, especially if you are over 40. Examination and referral when needed take days, not months.

NHS bowel cancer screening

The FIT (faecal immunochemical test) detects hidden blood in stool:

  • sent to your home every two years if you are eligible
  • you collect a small sample and post it back in a prepaid envelope
  • results arrive by letter within about two weeks

A positive FIT result means blood was detected — you will be offered colonoscopy to look inside the bowel. Most people with a positive FIT do not have cancer — polyps or other causes are common — but investigation is essential.

Current eligibility (England): ages 60 to 74, expanding to include people from age 50. Check NHS bowel screening for updates.

Complete your kit when it arrives — screening uptake saves lives.

When to see a GP (at any age)

See a GP without waiting for screening if you have:

  • blood in poo — any age
  • change in bowel habit for 3+ weeks
  • unexplained weight loss
  • persistent abdominal pain
  • anaemia on blood tests

Bowel cancer in people under 50 is less common but not rare — do not dismiss symptoms because of your age.

What happens after referral

A GP may examine your abdomen and perform a rectal examination, arrange blood tests, and refer you on the urgent suspected cancer pathway if needed. Investigation usually involves colonoscopy — a camera examination of the bowel under sedation.

Most referrals do not find cancer — but fast assessment provides reassurance or early treatment.

Risk factors

  • Age — most cases over 60, but younger cases occur
  • Family history — especially first-degree relatives diagnosed under 50
  • Inflammatory bowel disease — Crohn’s disease, ulcerative colitis
  • Inherited conditions — Lynch syndrome, familial adenomatous polyposis
  • Lifestyle — smoking, alcohol, red and processed meat, obesity, low fibre intake

Most people with bowel cancer have no family history.

Reducing your risk

  • complete screening when invited
  • eat plenty of fibre — fruit, vegetables, wholegrains
  • limit red and processed meat
  • maintain a healthy weight
  • exercise regularly
  • stop smoking and limit alcohol

Treatment overview

Treatment depends on stage and location:

  • Surgery — removes the cancer and nearby lymph nodes; often curative if caught early
  • Chemotherapy — before or after surgery for some stages
  • Radiotherapy — mainly for rectal cancer
  • Targeted and immunotherapy — for advanced disease in some cases

Early-stage bowel cancer has high cure rates. Late diagnosis reduces options — another reason to act on symptoms promptly.

After a diagnosis

Bowel cancer care involves specialist teams — surgeons, oncologists, nurses, and support services. Many people return to normal life after treatment. Macmillan and Bowel Cancer UK provide practical and emotional support.

If you have noticed blood in poo or unexplained weight loss, see our dedicated symptom guides — but always follow up with a GP for assessment, not self-diagnosis.

Common questions

What are the symptoms of bowel cancer?
Persistent change in bowel habit, blood in poo (often without pain), unexplained weight loss, abdominal pain or bloating, extreme tiredness from anaemia, and a feeling that the bowel does not fully empty. Early cancer may cause no symptoms — which is why screening matters.
What is bowel cancer screening?
The NHS sends faecal immunochemical test (FIT) kits to eligible adults every two years. You collect a small stool sample at home and post it back. A positive result needs follow-up colonoscopy — it does not mean you have cancer, but investigation is important.
Who gets bowel cancer screening in the UK?
In England, people aged 60 to 74 receive FIT kits, with expansion to age 50 underway. Scotland, Wales and Northern Ireland have similar programmes with slightly different age ranges. Check nhs.uk for current eligibility.
Am I at higher risk of bowel cancer?
Risk increases with age, family history of bowel cancer, inflammatory bowel disease (Crohn's, ulcerative colitis), Lynch syndrome, and lifestyle factors — smoking, alcohol, red/processed meat, obesity and inactivity. Most cases occur without a family history.
How is bowel cancer treated?
Surgery to remove the cancer is the main treatment. Chemotherapy, radiotherapy, and targeted medicines may be used depending on stage and location. Early detection through screening or prompt GP referral gives the best outcomes.

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