Why Colon Cancer Screening Matters

Colorectal cancer is one of the most common and preventable cancers worldwide. With regular screening, colon cancer can be detected early—when it’s most treatable—or even prevented entirely by removing precancerous polyps. Yet many people delay or avoid screening, putting their health at risk unnecessarily.

What Is Colon Cancer?

Colon cancer begins in the large intestine (colon) or the rectum, typically starting as small, noncancerous growths called polyps. Over time, some of these polyps can develop into cancer. Screening is the most effective way to find and remove polyps before they turn into cancer.

Who Should Be Screened?

The general recommendation is to begin colon cancer screening at age 45 for people at average risk. However, those with higher risk may need to start earlier. You may be at increased risk if you have:

  • A family history of colon cancer or polyps
  • A personal history of inflammatory bowel disease (IBD), including Crohn’s or ulcerative colitis
  • Inherited syndromes such as Lynch syndrome or FAP
  • Previous polyps or colorectal cancer
  • Black or African American ancestry (higher risk group)

Types of Colon Cancer Screening Tests

There are several effective screening options. Your doctor can help determine which is best based on your age, history, and preferences.

Colonoscopy

Frequency: Every 10 years (if normal results)

Considered the gold standard, a colonoscopy allows doctors to view the entire colon and remove polyps during the same procedure. It requires bowel preparation and sedation but provides the most comprehensive assessment.

Fecal Immunochemical Test (FIT)

Frequency: Annually

This test checks for hidden blood in the stool, which may indicate cancer or large polyps. It’s easy to do at home but less accurate than a colonoscopy. A positive result requires follow-up with a colonoscopy.

Stool DNA Test (e.g., Cologuard®)

Frequency: Every 3 years (if normal)

This at-home test detects DNA changes and hidden blood associated with cancer. It’s more accurate than FIT but still requires a colonoscopy if positive.

Flexible Sigmoidoscopy

Frequency: Every 5–10 years

This test examines the lower part of the colon. It may miss lesions in the upper colon but is a useful option when colonoscopy isn’t feasible.

CT Colonography (Virtual Colonoscopy)

Frequency: Every 5 years

Uses CT imaging to look at the colon. It’s non-invasive but still requires bowel prep, and any abnormalities will need follow-up colonoscopy.

How to Prepare for Screening

For colonoscopy and other visual exams, you’ll need to follow bowel prep instructions to clean out your colon. This often involves a special liquid laxative and a clear-liquid diet the day before. For stool-based tests, preparation is minimal.

What If a Polyp or Cancer Is Found?

Polyps found during a colonoscopy are typically removed immediately. If cancer is detected, your doctor will discuss treatment options, which may include surgery, chemotherapy, or radiation, depending on the stage.

Barriers to Screening—and How to Overcome Them

  • Fear or anxiety: Modern screening techniques are safe and routine.
  • Embarrassment: Medical professionals handle these tests with respect and discretion.
  • Cost concerns: Most insurance plans, including Medicare, cover colon cancer screening with no out-of-pocket costs.
  • Lack of symptoms: Early colon cancer often causes no symptoms—screening is the only way to detect it early.

When to Reschedule or Stop Screening

Screening usually continues through age 75, depending on your health and life expectancy. After age 75, screening decisions are individualized. If you are older than 85 or have serious health issues, routine screening may not be recommended.

FAQs About Colon Cancer Screening

Is a colonoscopy painful?

No. It’s performed under sedation, so most people don’t feel discomfort during the procedure.

How long does a colonoscopy take?

The procedure itself takes about 30–60 minutes, but allow several hours for check-in and recovery.

Can polyps come back after removal?

Yes, which is why regular follow-up screening is essential.

What if I have no family history—do I still need screening?

Yes. The majority of colon cancers occur in people with no family history.

Is at-home stool testing accurate?

It can detect some cancers, but it’s less reliable than colonoscopy. Any positive test must be followed by a colonoscopy.

Can diet affect my risk?

Yes. A high-fiber, low-red meat diet may reduce risk. Smoking, alcohol, and obesity can increase it.

Final Thoughts from Your Gastroenterologist

Colon cancer is one of the most preventable and treatable cancers when caught early. Screening saves lives, and delaying it could mean missing the window to stop cancer before it starts. If you’re 45 or older—or have risk factors—schedule your screening today. Your future health depends on it.