Home Types of cancer Bowel Cancer

Bowel Cancer

Bowel cancer, also known as colorectal cancer, refers to cancer which develops in any part of the large bowel (colon) or rectum.

Quick facts about bowel cancerQuick facts about bowel cancer

  • Most bowel cancer starts with the development of growths, called polyps, on the inner lining of the intestine
  • Bowel cancer is the fourth most common cancer in the UK, with over 43,000 new cases every year*
  • More than nine out of ten new cases (94%) are diagnosed in people over the age of 50. But bowel cancer can affect anyone of any age. More than 2,600 new cases are diagnosed in people under the age of 50 every year**

Types of bowel cancerTypes of bowel cancer

Bowel cancer refers to both colon cancer and rectal cancer. 

Colon cancer Rectal cancer
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Colon cancer

Colon cancer originates in the large intestine, also known as the colon. In many cases, early signs of colon cancer include non-cancerous polyps in the colon.

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Rectal cancer

Rectal cancer develops in the end of the large intestine, known as the rectum. Like cancer found in the large intestine, it can begin with the formation of non-cancerous polyps.

Signs and symptoms of bowel cancer Signs and symptoms of bowel cancer

As signs and symptoms for bowel cancer can be similar to other common conditions such as haemorrhoids, it’s important to see your GP or healthcare professional if you experience any of the symptoms below. Discussing anything concerning with your doctor as soon as possible can help give you peace of mind and offer the best chance of successful treatment if you receive a bowel cancer diagnosis.

Symptoms may include:

  • Sudden changes in bowel movements, like diarrhoea, constipation, narrower stools, or stools that contain mucus

  • Unexplained weight loss or loss of appetite

  • Bright red or dark blood in your stool or on the toilet tissue

  • Pain in your stomach with or without swelling

  • Constant gas or bloating in the bowel or rectum

  • A lump or pain around the anus

  • Unexplained anaemia (low iron) which can cause tiredness and breathlessness

Stages of bowel cancerStages of bowel cancer

The TNM system is used to stage bowel cancer, and it helps doctors understand what your cancer looks like. The TNM stands for:

  • Tumour – The degree to which the tumour has affected other tissue, for example has it grown outside the wall of the rectum or colon
  • Node – Is a measure of whether lymph nodes have been affected
  • Metastasis – The degree to which the cancer has spread to other organs of the body

The TNM information, along with other tests, helps determine the stage of your bowel cancer using the guidelines below:

Stage 0 bowel cancer Stage I bowel cancer Stage II bowel cancer Stage III bowel cancer Stage IV bowel cancer
Stage 0 Bowel Cancer

Stage zero

The cancer is in its earliest stage and has not spread beyond the inner layer (mucosa) of the colon and rectum.

Stage 1 Bowel Cancer

Stage I

The cancer has been found in the mucosa and has spread beyond the inner layer of the colon or rectum to the submucosa, but not to the lymph nodes.

Stage 2 Bowel Cancer

Stage II

The cancer has spread beyond the layer of muscle surrounding the bowel and reached the outermost layers of the colon or rectum and surrounding areas, but has not spread to the lymph nodes.

Stage 3 Bowel Cancer

Stage III

The cancer has spread to the lymph nodes, but not to distant organs.

Stage 4 Bowel Cancer

Stage IV

The cancer has spread to distant organs (e.g. lung, liver, peritoneum) throughout the body.

Treatment for bowel cancer

There are many different types of treatment for bowel cancer. Your treatment will depend on you and your cancer.

Learn more

Frequently asked questions about bowel cancerFAQs

Is bowel cancer hereditary?

Bowel cancer can be hereditary. If you have a family history of bowel cancer, you may have the Lynch syndrome or Hereditary Non-polyposis Colon cancer (HNPCC). Enquire with your doctor about genetic testing.

What causes bowel cancer?

Genetic and Lifestyle risk factors: Being over 50, smoker, overweight, having a family history of bowel cancer, the presence of Lynch syndrome, having inflammatory bowel disease such as Crohn’s or Ulcerative Colitis.

How common is bowel cancer?
  • Bowel cancer is the fourth most common cancer in the UK, with over 43,000 new cases every year*
  • More than nine out of ten new cases (94%) are diagnosed in people over the age of 50. But bowel cancer can affect anyone of any age. More than 2,600 new cases are diagnosed in people under the age of 50 every year**
What can I do to decrease my risk of bowel cancer?

There are a number of lifestyle-related factors you can consider reducing your risk of developing bowel cancer, like:

  • Get regular exercise – at least 30 minutes of moderate-intensity exercise each day
  • Reduce your alcohol intake – If you choose to drink, try to limit your alcohol intake to no more than two standard drinks a day
  • Eat a healthy, balanced diet – Eat a fibre-rich diet from grain and legume sources, as well as enjoy a variety of fruit (2 serves) and vegetables (5 serves) per day, limit your intake of salt, saturated fats, and avoid all processed meat
  • Regular screening for bowel cancer – Screening for bowel cancer should be offered every 2 years to men and women between the ages of 50 and 74 in the UK using the faecal-immunochemical test (FIT).
Where can I find out more about bowel cancer screening?

For more information on bowel cancer screening, visit the Bowel cancer screening: programme overview.

More information

ReferencesReferences

For a full list of references, click here.
  1. Cancer Research UK. (2025, April 24). Bowel cancer statistics. Cancer Research UK. Retrieved May 7, 2025, from https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/bowel-cancer#:~:text=There%20are%20around%2044%2C100%20new,cases%20(2017%2D2019).
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