Colorectal screening can do two useful things. It can find cancer early, when it is easier to treat, and it can find polyps, small growths in the colon or rectum, so they can be removed before they have a chance to turn into cancer. That second job is why this screening matters so much, and why the starting age moved a few years ago.

This article covers who should be screened, the tests you can choose from, and what to do if you have symptoms.

When to start, and when to stop

The U.S. Preventive Services Task Force updated its colorectal cancer screening recommendation in May 2021. It recommends screening for all adults aged 45 to 75. For ages 50 to 75 the evidence is strongest (an A grade); the earlier start at 45 carries a B grade. For adults 76 to 85, the Task Force recommends deciding case by case, based on overall health, past screening results and personal preference. As of October 2026, the 2021 statement is still the current version.

Those ages are for people at average risk. The CDC notes that you may need to start before 45 or be screened more often if you have inflammatory bowel disease such as Crohn’s disease or ulcerative colitis, a personal or family history of colorectal cancer or polyps, or a genetic syndrome such as Lynch syndrome or familial adenomatous polyposis. If any of these apply, the schedule should be set with your doctor.

The test options

The Task Force lists several acceptable approaches rather than a single test. Each has its own repeat interval:

  • Colonoscopy, every 10 years. A doctor examines the whole colon with a camera and can remove most polyps during the same procedure.
  • FIT (fecal immunochemical test) or high-sensitivity guaiac stool test, every year. A kit you use at home to check stool for hidden blood.
  • Stool DNA test combined with FIT, every 1 to 3 years. Checks stool for blood and for altered DNA. The CDC describes it as an every-three-year test.
  • CT colonography, every 5 years. An imaging study, sometimes called virtual colonoscopy.
  • Flexible sigmoidoscopy, every 5 years, or every 10 years when paired with a yearly FIT. It looks at the rectum and the lower part of the colon only.

One point is easy to miss. With a stool test, CT colonography or sigmoidoscopy, an abnormal result means the next step is a colonoscopy. The CDC is clear that these tests need a follow-up colonoscopy when the result is positive, so a home test is the start of the process rather than the whole of it.

Choosing between them

Colonoscopy examines the entire colon and is the only option that can remove most polyps at the same sitting. It also involves bowel preparation the day before, sedation, and a ride home. Stool tests ask nothing of you beyond collecting a sample, but they have to be repeated on schedule to work, and a positive result leads to a colonoscopy anyway.

Some practical questions help narrow the choice:

  • Have you had polyps before? If so, follow-up is usually by colonoscopy on a schedule based on what was found.
  • Would you complete a yearly home kit reliably, every year?
  • Do you take blood thinners, or have heart or lung conditions that affect sedation? Your doctor will want to plan around them.
  • Do you split the year between Florida and another state? It helps to know where your last report lives and who will follow up a result.

On cost, the CDC notes that most health plans cover screening tests with no deductible or co-pay. Details vary by plan, so it is worth checking before you book, particularly for the follow-up colonoscopy after an abnormal stool test.

Symptoms are a different conversation

Screening is meant for people who feel well. Polyps and early cancers often cause no symptoms, which is the reason to screen. If you do have symptoms, you need a medical evaluation rather than a routine screening test. The CDC lists these possible symptoms:

  • A change in bowel habits
  • Blood in or on your stool
  • Diarrhea, constipation, or a feeling that the bowel does not empty all the way
  • Abdominal pain, aches or cramps that do not go away
  • Weight loss you cannot explain
  • Low iron levels in the blood (anemia)

Many other conditions cause these symptoms, and most are not cancer. Still, call your doctor rather than waiting for your next screening date. Heavy rectal bleeding, or bleeding with dizziness or fainting, needs emergency care.

For a broader look at lowering cancer risk, see our article on cancer prevention and risk factors.

At Legacy Medical, Dr. Shtern goes over your family history and past reports, helps you pick the test that fits, and offers stool occult blood testing in the office. If a colonoscopy is the right choice, she coordinates the referral and reviews the findings with you. Screening is part of preventive care here. To meet her first, the first visit is a complimentary meet and greet.

This article is general information, not advice for your situation. Members can call the office with questions about their own care.