Know your four options for colorectal screening

As with all types of cancer, early detection of colon cancer is the key to a much higher survival rate. The National Cancer Institute estimates there were 149,500 new cases in 2021 with an estimated 52,980 deaths. If colorectal cancer is detected early through screening, the five-year survival rate is about 90 percent.

Colorectal screening methods

You have more than one option when it comes to colorectal screening for colon cancer. Which type you choose will depend on your overall health family history, personal risk factors, and age. In some instances, your doctor might prescribe more than one type of screening.

Here are the four main options for colorectal cancer screening:

Colonoscopy

A colonoscopy involves a physician inserting a thin, flexible tube called a scope into your colon. The tube is lighted and has a small camera on the end. This enables the doctor to examine the entire length of your colon and rectum. As the doctor checks your colon, he or she looks for any changes that could indicate precancerous conditions. During the procedure, your doctor can take a sample or biopsy of any suspicious tissue or polyps. Polyps also usually are removed. You will most likely be sedated during the colonoscopy so you won't experience any discomfort.

Colonoscopies are repeated every 3-10 years, depending on if polyps are present. If there are polyps, you will need to repeat the procedure sooner.

Preparation for a colonoscopy is often considered more difficult than the procedure itself. Generally, you will need to consume a clear-liquid diet the day before the procedure. This preparation also will include taking strong laxatives intended to empty your bowel so the doctor can have a good look at your colon.

Flexible sigmoidoscopy

A flexible sigmoidoscopy is similar to a colonoscopy but more limited in scope. This test involves the doctor inserting a thin tube into the sigmoid colon, which is the last portion of the large colon. The specialist will examine this part of the colon and identify any changes or suspicious areas. He or she also will take a biopsy if polyps are found. The polyps might be removed during the procedure or you might have to undergo a colonoscopy later at which time the polyps will be removed.

If no polyps are found, this test will be repeated every 5 years. A yearly stool test also is performed. Preparation of your bowels might be required but the prep isn't as extensive as before a colonoscopy. Generally, you don't need sedation for this procedure.

CT colonography

Computed tomography (CT) colonography, also called a virtual colonoscopy, uses X-rays and computers to produce images of the entire colon, which are displayed on a computer screen for the doctor to analyze.

As with a colonoscopy, you will need to consume a clear-liquid diet the day before the procedure and take strong laxatives to empty your bowel.

This test will be done every 5 years.

Stool sample

Stool (feces) sample tests check for signs of cancer in the stool. Such tests are less invasive than other procedures and can generally be performed in the privacy of your home by you. You send the stool sample to a laboratory for testing. These tests don't require any preparation. They must be done more frequently than other types of tests, usually every 1-3 years.

If results are found to be abnormal, the stool sample will require a follow-up colonoscopy.

There are two main types of stool tests. The DNA stool test involves screening your stool for abnormal DNA markers that can indicate cancerous changes. One example of such a test is Cologuard. This is done every 3 years.

The stool blood test checks your feces for blood, as cancer can cause bleeding that ends up in the stool. This test is not conclusive, however, as blood in the stool also can be an indication of you having taken NSAID pain relievers such as ibuprofen or blood thinners. Hemorrhoids also can lead to blood in the stool. This test is repeated yearly.

The topic of colon cancer is a serious matter that can cause some anxiety. It helps to know effective tests exist that can detect colon problems early. Give yourself precious peace of mind by talking to your doctor and see if it is time to schedule your colorectal screening.

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