Bowel cancer

The bowel is part of the food digestive system. It joins the stomach to the anus (bottom) and helps waste material (poo) to leave the body. The bowel is made up of the small bowel, large bowel (colon) and rectum. Bowel cancer develops when abnormal cells in the colon or rectum grow in an uncontrolled way. The cells can form small growths called polyps, which can turn into cancer over time. Aotearoa New Zealand has one of the highest rates of bowel cancer in the world.


Symptoms of bowel cancer

There may be no warning signs that you have bowel cancer.

Common symptoms of bowel cancer may include:

  • a change in your normal bowel habit that continues for several weeks
  • blood in your bowel motion (poo).

These symptoms can be caused by conditions other than cancer. However, it is important to get them checked with your healthcare provider as soon as possible.


Risk factors for bowel cancer

The risk factors for bowel cancer are:

  • being over 50 years old
  • if you previously had polyps (adenomas) in the bowel and close family members who have had polyps in the bowel
  • having a family history of bowel cancer
  • having an inherited bowel cancer syndrome in your family, such as familial adenomatous polyposis (FAP), Lynch Syndrome or other rare conditions
  • having inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease.

Having one or more of these risk factors does not mean you will develop bowel cancer. Other risk factors that may increase your risk of bowel cancer that you can change are:

  • being overweight
  • smoking tobacco
  • having a diet with high processed food and red meat
  • having a low-fibre, high-fat diet
  • drinking alcohol.

Diagnosing bowel cancer

Bowel cancer may be identified after a:

  • screening test for cancer
  • visit with your healthcare provider if you have symptoms of bowel cancer.

If you have symptoms, the first test to check for bowel cancer is usually a colonoscopy.

About colonoscopy (internal link)

If bowel cancer is diagnosed, additional tests may be done to find out if the cancer has spread anywhere else on the body and the stage of the disease. These tests are usually a CT or an MRI scan.


Preventing bowel cancer

There is no certain way to prevent bowel cancer.

The most common risk are things you cannot change (like growing older).

You can reduce the risk of bowel cancer developing by:

  • having a balanced diet with fruit, vegetables and fibre
  • regular exercise
  • being smoke-free.

Finding bowel cancer early

Getting a bowel screening test every 2 years, starting at age 60 until the age of 74, is the best thing you can do to find bowel cancer early.

National Bowel Screening Programme (internal link)

See your healthcare provider if you develop symptoms of bowel cancer such as:

  • a change in your normal bowel habits that continues for several weeks
  • blood in your bowel motion (poo).

Treating bowel cancer

Treatment for bowel cancer depends on:

  • the type of cancer
  • the stage of cancer (how far it has spread)
  • the severity of your symptoms
  • your general health and preferences.

If you are found to have bowel cancer you will be referred to a specialist. 

The main treatment for bowel cancer is usually surgery. In some cases, chemotherapy (medicines to destroy cancer cells) or radiotherapy (radiation to destroy cancer cells) may be recommended.

Cancer treatments (internal link)


Cancer support

Once someone has been diagnosed with cancer, we know there are some difficult days ahead. No matter where you are on the cancer pathway, there is always someone to connect with for support.

There are local services available to help make things easier for you and your whānau, and support groups.

Cancer support (search) — Healthpoint (external link)

There are a number of benefits of belonging to a support group.

Health-based support groups (internal link)

Support and rehabilitation — Te Aho o Te Kahu - Cancer Control Agency (external link)