Bowel cancer is cancer in any part of the large bowel (colon or rectum). It is sometimes also known as colorectal cancer. Bowel cancer grows from the inner lining of the bowel (mucosa). It may develop from growths on the bowel wall called polyps.
On this page you will find information on:
- How common is bowel cancer?
- What are the risk factors?
- What are the symptoms of bowel cancer?
- How is bowel cancer diagnosed?
- What is the treatment for bowel cancer?
- What is the prognosis?
- What support is available?
How common is bowel cancer?
Bowel cancer is the second most common cancer affecting Australians. About 3,000 people in Queensland are diagnosed with bowel cancer every year. About one in 10 men and one in 14 women will develop bowel cancer before the age of 85. Bowel cancer is most common in people over 50, but it can occur at any age.
What are the risk factors?
While the exact cause of bowel cancer is not known, some risk factors increase the chance of developing it.
Risk factors include:
- getting older – bowel cancer most commonly affects people over the age of 50
- bowel diseases – people who have an inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis, have a significantly increased risk, particularly if they have had the disease for more than 8–10 years
- other diseases – people who have had colorectal cancer, and some people who have had ovarian, endometrium or breast cancer, are more likely to develop another bowel cancer
- lifestyle factors – being overweight, doing little physical activity, a diet high in fat or animal products, high alcohol consumption and smoking can play a part
- family history – if one or more close relatives (such as parent, sibling or grandparent) have been diagnosed with bowel cancer, the disease may run in your family
- inheriting a rare genetic disorder – two rare conditions cause a small number (5–6%) of bowel cancers: familial adenomatous polyposis (FAP) and Lynch syndrome
- Ashkenazi Jewish heritage – people from this background are more likely to develop bowel cancer
- benign bowel polyps – these non-cancerous growths can sometimes develop into cancer over a long period of time.
What are the symptoms of bowel cancer?
In its early stages, bowel cancer often has no symptoms. However, some people may experience the following:
- a change in bowel habits, such as diarrhoea, constipation, or smaller, more frequent bowel movements
- a change in appearance of bowel movements
- a feeling of fullness or bloating in the bowel or rectum
- a feeling that the bowel hasn’t emptied completely after a bowel movement
- blood in the stools or on the toilet paper
- weight loss
- weakness or fatigue
- rectal or anal pain
- abdominal pain or swelling
- unexplained anaemia
Not everyone who has these symptoms has bowel cancer. Other medical conditions, such as haemorrhoids or tears in anal tissue, can cause these changes. Some foods or medications can also cause changes in bowel movements. However, if you have any of the above symptoms for more than two weeks, see your doctor for a check-up.
How is bowel cancer diagnosed?
Your GP will do initial tests. Your GP can also refer you to a specialist if further tests are needed. Depending on your symptoms, you may have one or more of the following tests:
- Physical examination – your doctor will examine your body, feeling your abdomen for any swelling.
- Blood test – to assess your general health and to look for signs that you are losing blood in your stools.
- Flexible sigmoidoscopy – blows air into the bowel to allow doctors to see bowel wall clearly.
- Colonoscopy – a flexible tube with a camera on the end, called an endoscope, is inserted into your anus to examine the whole length of the large bowel.
Other tests include:
- CT scan – uses x-ray beams to take pictures of the inside of your body.
- MRI scan – uses magnetism and radio waves to build up very detailed cross-section pictures of the body.
- PET Scan – injection of radioactive glucose solution to highlight abnormal tissues in the body
- Ultrasound – uses soundwaves to build up a picture of your body.
Some tests may be repeated during or after treatment to check how well the treatment is working. Waiting for the test results can be a stressful time. It may help to talk to a friend or family member, a healthcare professional, or call Cancer Council on 13 11 20.
What is the treatment for bowel cancer?
Your medical team will recommend a treatment based on what you want, your general health, the location of the cancer in the bowel and the extent that the cancer has spread.
The most common treatment for bowel cancer is surgery. The aim of surgery for bowel cancer is to remove all of the cancer and nearby lymph nodes. The most common type of colon surgery is a colectomy. There are different types of colectomies depending on the tumour’s location.
For more information on the treatment of bowel cancer please refer to the Understanding Bowel Cancer booklet.
What is the prognosis?
Prognosis means the expected outcome of a disease. You may wish to discuss your prognosis and treatment options with your doctor, but it is not possible for any doctor to predict the exact course of your disease.
Test results, the type of cancer you have, the rate and depth of tumour growth, how well you respond to treatment, and other factors such as age, fitness and medical history are all important in assessing your prognosis.
In most cases, the earlier bowel cancer is diagnosed and treated, the better the outcome.
What support is available?
Whether you have been diagnosed with bowel cancer, or have a family member or friend who is affected by cancer, there are times when you may need support. Our professional services and support programs are here to help you.
Find out more about:
- Phone support
- Email support
- Cancer counseling
- Practical and financial support
- Support groups
- Information sessions