About colon cancer

Colon cancer is cancer of the large bowel (colon), which is the final part of your digestive tract. Rectal cancer is cancer of the last six inches of the colon. Together, they are called "colorectal cancer," or commonly called "colon cancer" or "bowel cancer."

Most cases of colon cancer begin as small, noncancerous (benign) growths called polyps. Over time, some of these polyps can become colon cancer.

People can be checked for colon cancer if they are:

  • average risk, defined as people ages 50 to 74 with no immediate relatives (for example, parent, brother, sister or child) who have or have had colon cancer
  • increased risk, defined as people with a family history of colon cancer that includes one or more immediate relatives (for example, parent, brother, sister or child)

People with average risk can get checked for colon cancer with an at-home test called the fecal immunochemical test (FIT). People with an increased risk can get checked with a colonoscopy.

The at-home test:

  • only takes a few minutes to do
  • requires only one stool sample (poop)
  • can be done without switching your diet or stopping your medications
  • should be done every two years, as long as you’re eligible and are at average risk

Colon cancer is a leading cause of cancer-related disease and death in Ontario for both men and women. But when colon cancer is caught early, nine out of 10 people with the disease can be cured.

Symptoms

There are often no physical symptoms during the early stages of the disease. As colon cancer develops over time, some or all of the following may occur:

  • unexplained anemia (a drop in red blood cell count) that is caused by low iron
  • blood (either bright red or very dark) in the stool (poop)
  • unexplained weight loss
  • new and persistent diarrhea, constipation or feeling that the bowel does not empty completely
  • new and persistent stomach discomfort

Learn more about colorectal cancer.

When to get checked

Get checked regularly to find colon cancer early when it is more likely to be cured. Regular testing can also find polyps that could turn into cancer. You should get checked even if no one in your family has had the disease.

Colon cancer usually develops later in life, with over 90% of cases diagnosed in people over age 50.

Encourage your friends and loved ones to get checked as well.

Get checked using an at-home test if you’re at average risk

You can do an easy-to-use at-home test if you’re at average risk for colon cancer. You are at average risk if you:

  • are ages 50 to 74
  • do not have a parent, sibling or child who has been diagnosed with colon cancer
  • have no signs or symptoms of colon cancer

Step 1: talk to a healthcare provider about getting a test

A healthcare provider must order an at-home test for you. To get an at-home test, you can:

  • talk to your family doctor or nurse practitioner
  • call Telehealth Ontario at 1-866-828-9213 if you do not have a family doctor or nurse practitioner
  • visit a mobile screening coach
  • contact your health centre or nursing station if you live in a First Nation community

Step 2: get a test mailed to you

LifeLabs will mail a test to your address of choice after your doctor or nurse practitioner has ordered you one.

Step 3: complete the test

The test is simple and only takes a few minutes to collect a sample (poop). You only need one sample, and you don’t have to change your diet or stop taking medication before taking the test.

Follow these easy steps:

  • Check your date of birth and name on FIT tube.
  • Write the date you collect your poop on the FIT tube.
  • Pee and flush before you poop (if you have to go).
  • Unfold the stool collection paper and put it inside the toilet bowl.
  • Sit on the toilet and poop on the collection paper.
  • Collect the sample using the FIT tube.
  • Flush your poop and the stool collection paper.

Learn more about how to complete the at-home test.

Step 4: return your completed test

Return your completed test as soon as possible to LifeLabs by:

If you live in a First Nation community, contact your health centre or nursing station to discuss drop-off options.

Step 5: get the results

After you get checked, Cancer Care Ontario will mail you a letter with the result of your at-home test (FIT). The letter you receive will tell you if your test results are normal, abnormal or unsatisfactory.

Your family doctor or nurse practitioner will also get a copy of your result.

If your result is normal

You should get checked again in two years using an at-home test. If you are still between the ages of 50 to 74, Cancer Care Ontario will send you a reminder letter.

If your result is abnormal

It means there is blood in your stool. This doesn’t necessarily mean you have cancer.

You’ll need to follow up with a colonoscopy to find out. It is recommended that you have a colonoscopy within eight weeks of an abnormal result from your at-home test.

Arrange next steps as soon as possible by contacting:

  • your family doctor or nurse practitioner
  • Cancer Care Ontario at 1-866-662-9233, if you don’t have a family doctor or nurse practitioner

Learn more about your at-home test results.

If your result is unsatisfactory

If your results are unsatisfactory, you must get a repeat test. A result that is unsatisfactory means that the test was rejected or invalid.

Get a colonoscopy if you’re at above-average risk

A colonoscopy is an exam where a doctor looks at the lining of the entire colon using a long, flexible tube with a tiny camera on the end.

It should be used if you’re at above-average risk for getting colon cancer, meaning  you have a family history of colon cancer that includes one or more parents, siblings or children with the disease. If this is the case:

  • Talk to your family doctor or nurse practitioner. You are at a higher risk of colon cancer and should get checked with a colonoscopy.
  • You should start getting a colonoscopy at age 50, or 10 years earlier than the age your relative was diagnosed with colon cancer, whichever comes first.
  • The amount of time you should wait until getting checked again after a normal result is based on your family history. Your doctor or nurse practitioner can advise on what is appropriate for you.

Learn more about colonoscopies.

Some people who have had polyps (growths that form on the lining of the colon or rectum) removed from their colon may be at increased risk of getting colon cancer and may need to be checked regularly with a colonoscopy instead of an at-home test.

People with inflammatory bowel disease (Crohn’s disease involving the colon and ulcerative colitis) may also be at increased risk for getting colon cancer and may need to get checked regularly with a colonoscopy instead of an at-home test.

If you do not have a family doctor or nurse practitioner, you can call Telehealth Ontario at 1-866-828-9213. If you live in a First Nation community, you can contact your health centre or nursing station.

Learn more about checking for colon cancer.

After your colonoscopy

The health care provider doing the colonoscopy should give your doctor or nurse practitioner your test results.

If your result is normal

Your doctor or nurse practitioner will advise on when you should next get a colonoscopy.

If your result is abnormal

Abnormalities including polyps, cancer or other diseases of the colon, may be found during a colonoscopy. The health care provider doing the colonoscopy should provide your test results and talk to you about next steps. This may include more tests and/or treatment.

Costs

OHIP pays for colon cancer screening with both the at-home test (FIT) and colonoscopy, so there is no cost to you.

Tips to reduce your risk

  • maintain a healthy body weight
  • be physically active
  • reduce alcohol intake
    • no more than two drinks a day for men
    • no more than one drink a day for women
  • eat a diet high in fibre (including vegetables and fruits)
  • limit red meat and processed meat (for example, bologna, salami)
  • don’t smoke or use tobacco products (for example, cigarettes, chewing tobacco)
  • get checked with the at-home test (FIT)

Remind your friends and family

If you have a loved one who is 50 or over and hasn’t been tested, encourage them to ask their doctor for the at-home test. Whether it be your parent, partner, sibling, child or friend, the chance of being cured is best when colon cancer is caught early.

Updated: September 02, 2021
Published: May 13, 2014