When & How Should I Be Screened For Colon Cancer?
July 30, 2025
Colon cancer, also known as colorectal cancer, is the third most common cancer in the United States, but it's also one of the most preventable.
Regular colon cancer screening is key to catching the disease early, when treatment is most effective. Learn why colon cancer screening is important, when you should be screened for colon cancer, and the ways you can have colon cancer screening.
Why Is Colon Cancer Screening Important?
Staying up-to-date on your colon cancer screening schedule is the single best way to ensure that you are cancer-free or that, if cancer is present, it is detected early while tumors are still small. Colorectal cancer often has no outward symptoms. So, even if you feel fine and believe your risk of colon and rectal cancer is small, you should still get screened.
When colon cancer is a stage 0 or stage I cancer, it drastically improves your survival rate.
What is stage 0 colon cancer?
Stage 0 colon cancer means that the cancer has not spread beyond the colon's inner lining.
What is stage I colon cancer?
Stage I colon cancer refers to tumors that have spread deeper into the colon wall but have not spread beyond the colon itself.
Most patients with colon cancer detected in stage 0 or stage I recover fully after surgery to remove the tumor - often with no chemotherapy or radiation required. Learn more about cancer stages.
When Should I Be Screened For Colon Cancer?
The American Cancer Society's colon cancer screening guidelines say the recommended age for your first colonoscopy or other routine colon cancer screenings is age 45. (That’s if you are not at a higher risk of colon cancer.)
After a normal colonoscopy or colon cancer screening test result, many patients at average risk for colorectal cancer won’t need to be screened again for 5-10 years, continuing until the age of 75.
Other colon cancer screening tests, because they are less comprehensive, are recommended on a more frequent basis than if you were getting a colonoscopy.
The American Cancer Society recommends:
- CT colonography (virtual colonoscopy) every 5 years
- Sigmoidoscopy every 5 years
- Stool-based tests as often as once a year
Colon cancer screening guidelines if you have higher risk
If you are at higher risk for colorectal cancer, such as if a family member had colon cancer, your doctor may recommend that you begin colon cancer screening earlier than age 45 and do so more often than every 5-10 years.
"For patients who at high-risk for colorectal cancer, at-home tests cannot be substituted - no exceptions," said John Underwood, MD, medical oncologist at Franciscan Health Indianapolis.. "High-risk patients include those with a personal or family history of colorectal cancer, those with a personal history of inflammatory bowel disease (Chron’s disease or ulcerative colitis), or certain genetic syndrome with a known increased risk, such as Lynch syndrome or familial adenomatous polyposis. Patients with worrisome symptoms, such as unexplained weight loss, changes in bowel habits, or rectal bleeding may not be candidates, either. And when in doubt, talk to your primary care provider for guidance."
“If you have a personal history of, for instance, certain inflammatory bowel disease like Crohn’s or ulcerative colitis, or if you have a family history of colon cancer or polyps, or there’s a few different genetic conditions out there…you wouldn’t bother with a Cologuard or any other test out there,” adds Narayan Prabhakar, MD, a Dyer, Ind., family medicine doctor with Franciscan Physician Network. "You would go right to a colonoscopy in those situations."
What Increases My Risk For Colorectal Cancer?
The American Cancer Society says people are considered at higher risk of colorectal cancer if they have these risk factors:
Colorectal cancer risk factors you can change
- Being overweight or obese
- Having a diet higher in red meat
- Being a smoker
- Using alcohol
- Not being physically active
Learn how diet and exercise can help improve your colon cancer risk.
Colorectal cancer risk factors you can't change
- A family history of colorectal cancer
- Previous colorectal cancer
- History of polyps
- Inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease
- Familial adenomatous polyposis (FAP)
- Lynch syndrome (hereditary non-polyposis colon cancer or HNPCC)
- A personal history of getting radiation to the abdomen (belly) or pelvic area to treat a prior cancer
- Your race. Colorectal cancer is more common in Native American and Black Americans, according to the American Cancer Society.
What Are The Screening Options For Colon Cancer?
Colon cancer screening test options include:
Colonoscopies
Colonoscopies are the gold standard for screening people who are at average risk for colon cancer.
"A screening colonoscopy is considered the gold standard for colorectal prevention due to having the highest detection rate of small tumors and polyps," said Dipen C. Maun, MD, a surgeon with Franciscan Physician Network Indiana and Colon and Rectal Specialists.
Colonoscopies are medical procedures that are done under anesthesia and offer the best chance of detecting early colon or rectal cancer. During a colonoscopy, patients are sedated. Then, a doctor uses a lighted tube called a colonoscope to examine the rectum and colon.
A colonoscopy allows the physician to detect any cancerous tumors and noncancerous growths called polyps.
If you are having a colonoscopy, doctors will remove any noticeable polyps to reduce your future risk of developing colorectal cancer. Polyps, while relatively common, may later become cancerous if not removed.
Other visual exams
Procedures such as flexible sigmoidoscopy allow doctors to directly view the colon and rectum for abnormalities. A flexible sigmoidoscopy is like a colonoscopy in that your doctor uses a flexible, lighted tube (sigmoidoscope) to see the lower part of your colon. You will still have to do bowel prep similar to that of a colonoscopy and may need a follow-up exam with a colonoscopy to view the entire colon.
A virtual colonoscopy, or CT colonography, uses a CT scan and X-rays to show abnormal areas, like polyps or cancer. It does not require you to be sedated but still requires the bowel prep like a colonoscopy.
Stool tests for colon cancer screening
If you are still leery of having a colonoscopy, there are less invasive options for colon cancer screening. For example, at-home stool sample tests check for blood and altered DNA in your stool, which are associated with the possibility of cancer or pre-cancer, but they are less effective at finding tumors or polyps.
"Colonoscopy is the gold standard and the preferred cancer screening test among oncologists," said Dr. Underwood. "However, for individuals without a personal or family history of colorectal cancer who are unable or unwilling to undergo a colonoscopy, at-home tests are a reasonable alternative, and I’ve seen many patients for whom a positive at-home test successfully led to the detection of colon or rectal cancer."
Stool tests are non-invasive tests that detect hidden blood in stool. Examples include FIT (fecal immunochemical test) and stool DNA tests. While stool tests can detect colon cancer, they are generally less sensitive than colonoscopy for detecting precancerous polyps. This means they might miss some polyps that could potentially develop into cancer.
If a stool test returns a positive result, a colonoscopy is required to confirm the finding, ensure it is not a false positive and potentially remove any polyps or cancerous tissue.
Blood tests for colon cancer screening
In 2024, the FDA approved a blood test for colon cancer. The main issue with blood tests is that, unlike colonoscopies, they often miss precancerous growths on the colon, and at a rate lower than the most advanced fecal tests. Check with your insurance plan about coverage of blood tests for colorectal cancer screening.
Understanding The Power Of Early Detection
According to the American Cancer Society, only 20% of adults under the age of 50 are up-to-date on their colon cancer screening. That matters because colon cancer is increasing in people under 50 years of age.
Rochelle Bowman expected to receive a clean bill of health when she went in for her first colonoscopy at age 51. After all, the mother of two grown children felt well, exercised regularly, and had no concerning symptoms.
However, during Rochelle's colonoscopy, doctors at Franciscan discovered she had stage I colon cancer. "They found a tumor that was a foot long," she said. "I feel very lucky to have found it before it spread."
Rochelle's cancer had not spread beyond her colon. Doctors were able to remove the tumor during a two-and-a-half-hour surgery.
For those putting off getting a colonoscopy, Rochelle's advice is simple: Don't.
"Everyone should get screened," she said. "It's an easy, minimally invasive procedure that everyone over 45 should be doing."
Talk with your provider to discuss the best colon cancer screening strategy for your healthcare needs. But above all, don't wait. If you haven't had a colon cancer screening and you're over age 45, make an appointment today.
“The earlier you can catch it, the better,” said Dr. Prabhakar. “With any cancer for that matter. And that's the key."
