Choices for Colon and Rectal Cancer Screening: Colonoscopy and Cologuard

There are multiple ways to test for colorectal cancer and colorectal polyps.

Colorectal cancer – cancer of the colon and rectum – is the third most common and second most deadly cancer for both men and women in the U.S. Luckily, there are multiple ways to test for colorectal cancer and colorectal polyps, which are precancerous growths of the lining of the colon and rectum. Below, we review two of the common tests your primary care provider (PCP) may recommend to screen for colorectal cancers.

What is colonoscopy?

Colonoscopy is a procedure in which a physician (either a surgeon or a gastroenterologist) uses a long flexible camera to inspect the inside of your colon and rectum. This is done while you are asleep. While many diseases can be diagnosed with colonoscopy, your physician will mainly be looking for signs of cancer or precancerous polyps. If an abnormality is seen during the procedure, your doctor will either remove it (called a polypectomy) or take a small piece of it out (called a biopsy) to be examined under a microscope.

What is Cologuard?

Cologuard testing is a type of stool test which detects abnormal DNA and/or blood in your stool. These can be signs of colorectal cancer or of precancerous polyps. This test is prescribed by your PCP, but you do the test at home. When you receive the kit, you follow the instructions to take some of your stool and mail it back to the company which makes the test. The company tests your stool and sends the results to your PCP. If the test is positive/abnormal, then you will need to get a colonoscopy.

What are the advantages of getting a colonoscopy?

Colonoscopy has several advantages:

1. It is considered the “gold standard” for detecting both cancers and precancers in the colon and rectum, meaning that it is the best test we have currently.
2. If an abnormality is detected during the colonoscopy, it can either be removed or biopsied at the same time.
3. If your colonoscopy is normal and you are at average risk of developing colorectal cancer (meaning that you have not had colorectal cancer or polyps before and you do not have a strong family history of colorectal cancer), then you may be able to go up to 10 years before needing another colonoscopy.
4. All insurances cover screening colonoscopies (those done when someone does not have symptoms of colorectal cancer, has not had a positive stool test, and does not have a history of colorectal cancer or polyps) without you needing to pay a deductible or copay.

What are the disadvantages of getting a colonoscopy?

Colonoscopy does have some drawbacks:

1. To get a good test, your colon and rectum need to be cleaned out before the test so that the camera can get good pictures. To do this, you must be on a liquids-only diet the day before the test. Then, you have to take medications to clean out your colon, which can be unpleasant (this is called a bowel preparation or colon cleanse).
2. Because you do the test at the hospital and get sedation for the test, you may have to take a day off from work.
3. While colonoscopy is overall very safe, there are small risks which can include bleeding, injury to the colon, the physician not being able to see the entire colon, or missing small abnormalities.

What are the advantages of Cologuard?

The main advantage of Cologuard is that it is easy to do.

1. You can do the test from home.
2. Sedation is not required, so you don’t have to miss work.
3. You don’t have to clean out your colon before doing the test.
4. Cologuard seems to be better than older generations of stool tests (fecal occult blood tests and fecal immunoassay tests) at detecting cancers and polyps.

What are the disadvantages of Cologuard?

Cologuard has some limitations:

1. Cologuard should not be used for anyone having symptoms of colorectal cancer such as unexplained weight loss, abdominal pain, changes in bowel habits, changes in stool size, or blood in or on the stools.
2. Cologuard should not be used for people with increased risk of colorectal cancer, including those who have had colorectal cancer in the past, those who have a history of polyps, those who have a disease or genetic syndrome which increases their risk of colorectal cancer, or those with a strong family history of colorectal cancer.
3. If the test result is positive/abnormal, then you have to get a colonoscopy for diagnosis, which will require a copay or deductible with your insurance.
4. The Cologuard test can produce both false positives (the test result is positive/abnormal, but you don’t have cancer or a polyp) or false negatives (the test result is negative/normal, but it missed a cancer or polyp that you do have).
5. With Cologuard, if you have a negative/normal result, you will need to repeat the test at least every 3 years as opposed to the 10 years between normal colonoscopies.

What is my next step?

If you have symptoms that might indicate colorectal cancer, talk to your PCP as soon as possible. He or she can assess your symptoms and then refer you to a gastroenterologist or general surgeon, as appropriate. If you don't have a PCP, you can use our "Find a Doctor" website feature or call us at (706) 389-3892 to find one.

If you do not have symptoms and are 45-50 years of age, talk to your PCP at your next wellness visit about when you should have your first screening exam. Again, if you need to find a PCP, visit our "Find a Doctor" feature or give us a call.

The general surgeons at Athens General and Colorectal Surgery, part of St. Mary's Medical Group, are highly skilled and experienced in performing colonoscopies and surgeries to treat colorectal cancer.

Learn More

---

About Davis Horkan, MD