Colorectal cancer (cancers that start either in the colon or rectum) is a highly treatable and often curable disease when it has not moved outside the bowel. This makes regular screenings important so that the cancer can be caught as early as possible if it arises.

While there are a few different screenings that can be done at home, they are designed to inform patients about when they should head in to see their doctor. They are not diagnostic tools (in other words, they cannot diagnose colorectal cancer). A diagnosis will always require a physician and a colonoscopy. Even so, at-home tests can be helpful for certain people.

Here, Jeffrey Meyerhardt, MD, MPH, co-director of the Colon and Rectal Cancer Center at Dana-Farber/Brigham and Women’s Cancer Center, answers some commonly asked questions about colon cancer screenings.

When should I start screening for colon cancer?

Typically, most people begin annual screening after the age of 50 — but there is increasing support for people to begin screenings at the age of 45, as we are seeing a relatively increased incidence of colorectal cancer in people less than age 50. If there is a history of colorectal cancer or colorectal polyps in your family, then it is usually recommended to start screenings earlier. Screenings are done through a colonoscopy procedure.

If you are experiencing certain symptoms, it may be a good time to talk to a physician. The most commonly thought of symptom is bleeding, but another common one is if you’ve seen a change in your bowel habits; whether that be consistent constipation, a change in urgency, difficulty passing stool, or abdominal bloating.

If you experience symptoms like these but they fully resolve in a week or so, it is likely less worrisome and you can follow to see if symptoms recur. If the symptoms last for several weeks and keep coming back intermittently, then it is time to seek medical attention.

Are there colorectal cancer tests I can take at home?

There are a few different tests that can be done at home, but none of them result in a diagnosis. They are:

  • Stool cards, or what’s called a “FIT test,” which test for blood in the stool
  • Tests that look for altered DNA and blood in the stool (one example is Cologuard)

A positive result will require a doctor’s visit and a colonoscopy to give an accurate diagnosis.

How do I know if an at-home colorectal cancer test is right for me?

The most sensitive and accurate screening is a colonoscopy. Not only can a colonoscopy detect colorectal cancer but it can also find polyps, which are precursors to cancer. If you are experiencing symptoms, you should have a colonoscopy and not an at-home test. 

At-home colorectal cancer tests are an option for patients that are experiencing no symptoms and are appropriate for screening for colorectal cancer.  If your doctor is recommending screening for colorectal cancer, you can discuss with him/her if an at-home test would be a good option for you.

Is it safe to be screened for colon cancer during COVID-19?

Don’t let COVID-19 keep you from your regular health checkups, regular screenings included. Health care providers and facilities, including Dana-Farber, have taken many precautions to protect patients that come for visits as well as procedures, like colonoscopies.

To learn how your provider is protecting you during the pandemic, you should contact their office. Learn more about what Dana-Farber is doing to protect patients and staff.

This article was originally published on October 2, 2020, by Dana-Farber Cancer Institute. It is republished with permission.