Colon and Rectal Cancer: What you need to know

Mary Kwaan, MD

Colon and Rectal Surgeon

Department of Surgery 

University of Minnesota


“Colonrectal cancer is a preventable disease and is often cured when detected early”, Dr. Mary Kwaan.


Screening for colorectal cancer is recommended for men and women at or over the age of 50 and is recommended for African Americans over the age of 45. Yet millions of people in the United States are not being screened for colorectal cancer.

Screening is the best method for early detection

How do I get screened?

Your physician will be able to help you schedule a colorectal cancer screening appointment.

The most common method of screening is a “stool card”: either a fecal occult blood test (FOBT) or fecal immunochemical test (FIT) to test for blood in the stool. If the result is positive, your physician will schedule a colonoscopy.

A colonoscopy is an outpatient surgical procedure. During a colonoscopy, the colon and rectum are examined for early cancer or the presence of polyps. A polyp is a small growth, usually the size of a kernel of corn. Some polyps, if not removed can become cancerous. Everyone over age 45 should be tested for diabetes, especially if they are overweight

People who are overweight and under 45 years of age have a higher risk for developing diabetes and should be screened

What are the side effects of a colonoscopy?

To prepare for the test, the bowel must be cleansed by taking laxatives to induce diarrhea, which can be time consuming and can cause nausea in some patients.

There is a small risk, (1 in 1000) of perforation or popping of the colon during a colonoscopy. Also, if polyps are removed during the procedure, the area could bleed, but this is also uncommon. Finally, nearly everyone needs intravenous (IV) medications to relax during the procedure and there can be some risk with sedation, if other medical conditions are present.

Colorectal cancer is known as a “silent” disease because, in its early stages, there are often no symptoms

What are the symptoms of colorectal cancer?

Again, many people with colon cancer have no symptoms and screening is the best method for early detection. The most common symptom is blood in the stool. Typically, colon cancer is not painful unless it is more advanced. Changes in bowel movement patterns such as constipation, looser and more irregularly timed bowel movements or mucus around the stools are often symptoms of colorectal cancer.

Can colorectal cancer be a problem in young people?

Unfortunately, there has been a small rise in the rate of colorectal cancer in people under 50 years of age. Young people need to seek medical attention for symptoms, such as blood in the stool.

I don’t have any family members who have had colorectal cancer: Can I still get it?

Yes, colorectal cancer can affect anyone. The majority of people who get colorectal cancer do not have a family history. If you have a strong family history, for example more
than one person with colorectal cancer in your family, or someone who was diagnosed with colorectal cancer before they turned 50, you may need to have your screening earlier than age 50. This is something to discuss with your doctor.