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Colorectal cancer (colon and rectum)


In Québec, colorectal cancer, commonly known as colon cancer, is the 2nd leading cause of cancer-related deaths among men and the 3rd among women. This cancer forms in the rectum or colon (large intestine). It usually develops on polyps. Polyps are small masses of flesh that look like warts. They grow on the inner lining of the large intestine. 

Polyps can be benign (harmless), or they can develop into cancer. It can take years for a polyp to develop into a cancer.


Colorectal cancer generally develops slowly, without any apparent symptoms. If symptoms appear, they may be manifested in the following ways:

  • Persistent change in bowel habits:
    • Diarrhea or constipation
    • A feeling of incomplete stool evacuation
    • Unusual pain during stool evacuation
  • Abdominal pain or discomfort, such as stomach aches, flatulence and bloating
  • Blood in stools (black or bright red stools)
  • Bleeding after stool evacuation
  • Inexplicable weight loss
  • Extreme fatigue

Consulting a doctor

If you present one of the symptoms described for some time, you should consult a doctor. However, these symptoms may not necessarily be due to a cancer. Other health problems can also be the cause.


When someone is diagnosed with colorectal cancer, a team specialised in oncology establishes a personalised treatment plan with the patient. This treatment plan may vary depending on different elements, such as the type of cancer, the stage, and the patient’s general health. The treatment plan also takes into account the wishes and concerns of the person affected and those of his or her family. 

When cancer affects the large intestine, the main treatment options are surgery and chemotherapy. Radiotherapy may be prescribed to treat rectal cancer. The doctor may prescribe one, or a combination of these treatments.

Protection and prevention

Healthy lifestyle

The best way to reduce your risk of getting colorectal cancer is by living a healthy lifestyle:

  • Avoid smoking
  • Do at least 30 minutes of moderate to intense physical exercise a day
  • Maintain good eating habits:
    • Limited alcohol consumption
    • Limit intake of red meat and processed meats (bacon, sausage, salami, etc.)
    • Eat lots of fruits, vegetables and fibres
    • Opt for whole grains
  • Maintain a healthy weight


Colorectal cancer screening aims to detect cancer at an early stage, before signs and symptoms of the disease appear. The chances of a successful treatment are best in that period.

Who is eligible for screening 

Screening is mostly for people at average risk. It is recommended that people between the age of 50 and 74 at average risk (without symptoms and other risk factors) get screens for colorectal cancer every 2 years.

The immunochemical fecal occult blood test (iFOBT) is the recommended screening method for most of these people. Check with a health care professional to find out if you are eligible for an iFOBT or colonoscopy.

If you have a family doctor, you can get a prescription and your health care professional will tell you where to get a test kit.

If you do not have a family doctor, you can make an appointment at a local Service Point by going to the Clic Santé site or by calling 1 877 644-4545.

Book an appointment 

During your appointment, a health care professional will do a brief assessment to check if you are eligible for a screening test and will discuss the advantages and disadvantages of participating or not participating in screening with you.

If you are eligible for an iFOBT and, following an informed decision-making process, you want to do the test, a test kit and instruction sheet will be given to you so that you can collect the sample at home. Your participation in screening is voluntary. Screening is an option, never an obligation.

People at risk

Average risk

Age is the most common determining factor for colorectal cancer. The risk of having colorectal cancer increases from the age of 50. From the age of 50, everyone is at some risk of having colorectal cancer. This is referred to as an ‘average risk’.

Higher risk

Regardless of their age, some people are more at risk than others of developing colorectal cancer. This is particularly the case for people:

  • Who have already had colorectal cancer
  • Whose father, mother, brother, sister or child has had colorectal cancer
  • Who have had colorectal polyps
  • Who suffer from certain diseases of the intestines such as ulcerative colitis or Crohn's disease
  • Who have certain hereditary diseases such as familial adenomatous polyposis

People at high risk of developing colorectal cancer must consult a health professional. The health professional determines the screening method according to each person’s specific condition.

A few statistics

  • In Canada, about 1 in 14 people will develop colorectal cancer over the course of their life
  • Each year, approximately 6,800 Québecois are diagnosed with colorectal cancer
  • Colorectal cancer is the second leading cause of cancer-related deaths in people aged 50 to 74
  • Approximately 2,550 people die from colorectal cancer every year in Québec
  • Nearly 95% of colorectal cancer cases are manifested after 50 years of age

Last update: February 5, 2024


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