Diagnosing Colorectal Cancer

Your doctor may suspect you have colorectal cancer after receiving results from a regular screening test, from a physical examination or from your medical history.   To confirm a diagnosis your doctor will arrange special tests to identify if there is cancer and to decide on a treatment plan.  Waiting for a diagnosis can be stressful, talk to your doctor or nurse practitioner about what you can during this difficult time.

To find out more information, your doctor will order one or more of the following tests:

  • Endoscopy – an endoscopy uses a thin, flexible tube with a light and lens on the end (called the endoscope) to examine an organ or other part of the body. It is done to check for colorectal cancer if you have blood in your stool or other signs or symptoms.
  • A colonoscopy is a type of endoscopy that looks inside the entire colon and rectum. It is the most common test used to diagnose colorectal cancer.
  • A sigmoidoscopy may be used in some cases to look at the last part of the colon (called the sigmoid colon) and rectum.
  • Biopsy – A biopsy is needed to make a definite diagnosis of cancer. A biopsy is usually done during a colonoscopy or sigmoidoscopy to remove polyps or small amounts of tissue from the colon or rectum. Samples of the tissue are then looked at closely under a microscope. 

  • Blood tests – blood is taken to see if the different types of blood cells are normal in number and how they look.

  • Imaging Tests – X-rays, ultrasounds, CT scans or MRIs are used to look at your tissues and organs in more detail. They can see the size of a tumour and if it has spread.

To learn more about colorectal cancer, please visit the Canadian Cancer Society website available here or read Colorectal Cancer: Understanding Your Diagnosis here.

Information courtesy of Canadian Cancer Society