Most people should get screened for colorectal cancer starting at age 45. Cells in the large intestine can form polyps, which may turn into cancer over time. Detecting these polyps early means you have a chance to get them removed before they become cancerous.

“What’s the best cancer? The one that you don’t get. Not just the one that’s easily treated, but the one that never manifests itself. That’s why screening is so valuable and so important,” Robert Schoen, MD, a board-certified gastroenterologist at UPMC and professor of medicine at the University of Pittsburgh, told Verywell Health.

Despite the screening recommendation, many people aged 45 and older have not received regular colorectal cancer screening. Some avoid colonoscopies because the test seems complex, expensive, embarrassing, or painful. To address these barriers, the Food and Drug Administration (FDA) has approved a blood test and noninvasive at-home stool tests.

With many new tests available, is colonoscopy still considered the gold standard for colorectal cancer screening? Here’s what gastroenterologists say.

Is Colonoscopy Still the Best Way To Screen Colorectal Cancer?

Colonoscopy remains the gold standard for screening colorectal cancer because a provider can actually remove polyps during the procedure to lower cancer risk.

“Colonoscopy has certain advantages. It’s a one-stop shop. You have the colonoscopy, if there are polyps, we take them out, and you’re done,” Schoen said.

Before the procedure, you must do “bowel prep” to clean out your colon. This uncomfortable part of the process deters some people from scheduling a colonoscopy. The provider will insert a thin tube with a small camera into the patient’s anus. You will likely need sedation during the procedure, so someone will have to drive you home afterward, and you may miss a day of work.

If everything looks normal in the colon, you can wait 10 years before your next colonoscopy.

But, these tests can have a higher price tag than other types of colorectal cancer screenings. Private insurance and Medicare should cover colorectal screening tests for people starting at age 45, but check with your insurance provider first to determine if polyp removals or biopsies come with an additional charge.

“Colonoscopy is the preferred and the gold standard, but at least it’s helpful to know that there are stool as well as blood-based screening options. Having some screening option is better than no screening option,” Pashtoon Kasi, MD, medical director of GI Medical Oncology at City of Hope Orange County, told Verywell.

How Do Stool Tests Compare To Colonoscopy?

Stool-based screening tests could be a good alternative to colonoscopies since you can take these tests at home without doing any bowel prep.

There are three types of stool-based screenings: stool DNA test (Cologuard), fecal immune test (FIT), and guaiac fecal occult blood test (FOBT). Cologuard detects DNA changes associated with polyps or tumors, while FIT and FOBT look for signs of hidden blood that can signal polyps or colorectal cancer.

Regardless of which stool test you pick, you need to send a sample of your stool to a lab for tests.

“If the stool test is positive, you must get a follow-up colonoscopy. And unfortunately, we have a lot of instances where people have a positive test, and they don’t go through with the colonoscopy, so that’s kind of an opportunity lost,” Schoen said.

Stool tests are not perfect. They can miss polyps and must be re-taken every one to three years. And, if you don’t follow up with a colonoscopy following a positive test, you won’t get the full benefit of cancer screening and prevention.

How Do Blood Tests Compare To Colonoscopy?

The FDA has approved two blood tests for colorectal cancer: Epi proColon and Shield. These help detect the DNA from cancer or precancerous cells that shed into the blood as cancer grows, according to Kasi.

You can get a blood test at a clinic or your primary doctor’s office. You won’t need to do bowel prep or follow a specific diet before getting the test like you would with a colonoscopy.

“It can fill the practical void of folks who may or may not be willing to get a colonoscopy. And, as human beings, you can’t just give a stool sample on demand. You can easily do [a blood test] with your primary care office,” Kasi said.

Blood tests provide a noninvasive option for people who would otherwise skip colorectal cancer screening. However, like stool tests, a positive result requires a follow-up colonoscopy.

Blood tests are “better than nothing,” but they’re still not as good as the stool test or a colonoscopy, Schoen said. The blood tests only detect about 12–13% of advanced polyps, he added.

Which Screening Option Is Right for You?

Each test has pros and cons. Think about the cost, insurance coverage, and how often you have to repeat each test when deciding which one is right for you. For example, you only need a colonoscopy once every 10 years, but you need a FIT every year.

It is important to consult your healthcare provider about your screening options. Depending on your family history or certain risk factors, you may need to start testing before the recommended age of 45.

People who have a strong fear of colonoscopy, but are willing to consider this procedure in case of a positive result from other tests, may benefit from the stool or blood-based methods, said Reid M. Ness, MD, a gastroenterologist and an associate professor of medicine at Vanderbilt University School of Medicine.

“I think the patient needs to be honest with themselves. What are they willing to do? Can they get in every year to have a FIT test done?” Ness said. “If you have a positive test and nothing is done about it, then it’s a loss.”