How At-Home Tests Compare to Colonoscopies

Without question, colorectal cancer screenings can save lives. In fact, the number of colorectal cancer cases in the U.S. has been decreasing steadily since the mid-1980s in large part due to increased screenings, specifically colonoscopies. 

Despite evidence demonstrating the value of colonoscopies, only two-thirds of adults aged 50 and over opt to get one. Whether motivated by fear, embarrassment, or discomfort related to the all-necessary prep, the decision to forgo the procedure can have dire consequences. 

But there is good news for colonoscopy-averse individuals with an ‘average risk’ for colon cancer: at-home screening tests.

Currently, there are three types of at-home tests approved by the Food and Drug Administration. Designed to specifically look for trace amounts of blood or other substances that can be indicators of a growth in the colon in a provided stool sample, test kits are mailed to your home for sample collection. Once completed, they can be returned by mail or dropped off at a lab or your doctor’s office for testing. In instances where the test comes back positive, a diagnostic colonoscopy will likely be scheduled as part of your follow-up. Unlike a screening colonoscopy that is widely covered by insurance, a diagnostic one may include out-of-pocket costs such as co-pays or deductibles.

Again, at-home tests are only appropriate for individuals at average risk for colon cancer.  Anyone with any of the following risk factors should not rely on at-home tests:

• A personal or family history of colon cancer
• A personal history of precancerous colon polyps
• Inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis
• Any current or recent visible blood in the stool, that could result in a “false positive”
• A genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).

In addition, home tests are not an option for anyone taking blood thinners (Coumadin, Xarelto, or Eliquis) as it can lead to false positives.

And while at-home tests provide a convenient way to skip the unpleasant prep necessary for a colonoscopy, they aren’t without limitations. Specifically, they aren’t designed to detect polyps, the growths that can turn into cancer. A colonoscopy not only provides the opportunity for your doctor to look for pre-cancerous polyps but allows for any concerning polyps to be removed during the procedure.

Simply put, for individuals who are at average risk for colon cancer, at-home tests are a better option than no screening at all. If you fall in that category, be sure to discuss your options with your doctor.

If you have an above-average risk or have symptoms including bleeding or a change in bowel habits, a colonoscopy is a much better option for detecting and dealing with problems early. 

Dr. David Furman is a board-certified gastroenterologist at Southwestern Vermont Medical Center.