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What’s The Difference Between a Colonoscopy and a Cologuard test?

The American Cancer Society recommends that people of average colorectal cancer (CRC) risk start regular screening at age 45. Patients can either do a sensitive test, which is a stool-based test (like Cologuard) that looks for signs of cancer in a person’s stool, or a visual exam that looks at the colon and rectum. People who may be apprehensive to get a colonoscopy may opt for a less invasive test, however many are not aware of the limitations and cost differences before choosing between the screening tests. They may be looking for a test that can replace a colonoscopy without realizing the downsides of that decision.

What is Cologuard?

Cologuard is a stool DNA test that detects DNA mutations and detects precancer and cancer, if present, from a full stool sample. It is a non-invasive test that can be done from home and then mailed out to a lab for analysis. This test should be repeated every three years.

What is a Colonoscopy?

Colonoscopy is the gold standard screening test for colorectal cancer that detects and prevents cancer. The procedure involves your gastroenterologist inserting a colonoscope (a flexible tube with a light and small camera) and guiding it to the end of the colon. If a polyp is found, the doctor can painlessly remove it at that time and send it to a lab for examinations. Learn more about colonoscopies.

Cologuard vs Colonoscopy

How the two compare:

  • According to GI Alliance, Cologuard can miss up to 8% of colon cancer and more than 50% of pre-cancerous polyps.
  • Stool DNA (Cologuard) testing is designed to detect and not prevent cancer. A colonoscopy is the only test that both detects and prevents colon cancer.
  • Negative stool DNA (Cologuard) tests should be repeated every 3 years. Screening colonoscopies typically only need to be repeated every 10 years for people at average risk.
  • Most insurance providers will 100% cover a stool DNA (Cologuard) test in patients over the age of 45. However, if the test results in a positive, a “diagnostic” colonoscopy will need to be done with the cost of the “diagnostic” coming out of the patient’s deductible.
  • Screening colonoscopies are typically covered 100% by most insurances for patients 45 and older and include polyp removal during the same procedure.
  • Because of the 12% false-positive rate of stool DNA (Cologuard) tests, the cost for most patients’ deductibles will increase over the 10-year screening period.
  • Stool DNA (Cologuard) is not indicated for high-risk patients (family history of CRC, IBD, personal history of polyps) or for those with gastrointestinal symptoms.
Cologuard Test - Colon Cancer Stages
Colon cancer starts out as pre-cancerous polyps that can be removed during a colonoscopy, but many go undetected with Cologuard tests.


While a Cologuard test may sound like a less scary alternative to undergoing a colonoscopy, the whole colonoscopy procedure is painless, typically only needs to be repeated every 10 years, and is the best test for colorectal screening.

Because of the overwhelming success of colon cancer detection by screening colonoscopies, the disease has become one of the most preventable forms of cancer. Colon cancer is highly treatable with 90% of patients beating it when detected early. The bottom line is that there is no true replacement for a colonoscopy.

The best way to prevent colon cancer is to get screened, schedule an appointment or learn more about how Gastroenterology Consultants of San Antonio specializes in easy-prep colonoscopies in the San Antonio communities of Medical Center, Stone Oak, Northeast, Westover Hills, Boerne or Bulverde, call 210.614.1234 today.


Source: American Cancer Society

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