Colon Cancer Screening: Why Starting at 45 Could Save Your Life

Colorectal cancer — cancer of the colon or rectum — is the second leading cause of cancer death in the United States, claiming about 53,000 lives each year. Yet it is also one of the most preventable cancers we know of.

The reason: colorectal cancer almost always begins as a small, noncancerous growth called a polyp. Polyps grow slowly — often over 10–15 years — before becoming cancerous. Screening can find and remove polyps before that happens, stopping cancer before it starts.

If you are 45 or older and have not been screened, this post is for you.

For years, colorectal cancer screening was recommended starting at age 50 for average-risk adults. In 2021, the U.S. Preventive Services Task Force (USPSTF) lowered the recommended starting age to 45, and the American Cancer Society had already made this change in 2018.

Why the change? Rates of colorectal cancer in adults under 50 have been rising steadily for decades — a trend that is not fully understood but is well documented. Lowering the screening age is expected to prevent thousands of additional deaths each year.

• Ages 45–75: Screening recommended for all average-risk adults (Grade B recommendation)
• Ages 76–85: Discuss with your doctor — the decision depends on your health, prior screening history, and personal preferences
• Over age 85: Screening not recommended

• Starting at age 45: Regular screening for average-risk adults
• Continue through age 75
• Ages 76–85: Individual decision based on health status and preferences
• Over 85: No longer recommended

You are considered average risk if you do not have:

• A personal history of colorectal cancer or certain types of polyps
• A personal history of inflammatory bowel disease (Crohn's disease or ulcerative colitis)
• A family history of colorectal cancer or certain polyps
• A confirmed or suspected hereditary colorectal cancer syndrome (such as Lynch syndrome or FAP)

If any of these apply to you, you are at higher risk and should begin screening earlier — often at age 40 or even younger, depending on your specific situation.

One of the advantages of colorectal cancer screening is that you have choices. Tests fall into two categories: stool-based tests and visual (structural) exams.

These tests look for signs of cancer or polyps in a stool sample. They are non-invasive and can be done at home.

Fecal Immunochemical Test (FIT)

• Detects hidden blood in the stool
• Done at home; one sample per year
• Recommended frequency: Every year
• If positive, a colonoscopy is needed

High-Sensitivity Guaiac Fecal Occult Blood Test (gFOBT)

• Also detects hidden blood; requires dietary restrictions before the test
• Recommended frequency: Every year
• If positive, a colonoscopy is needed

Multi-Target Stool DNA Test (Cologuard)

• Detects both blood and abnormal DNA shed by cancer or polyp cells
• Done at home; no dietary restrictions
• Recommended frequency: Every 1–3 years
• If positive, a colonoscopy is needed
• More sensitive than FIT alone, but also has a higher false-positive rate

These tests directly examine the inside of the colon and can both detect and remove polyps in the same procedure.

Colonoscopy

• The gold standard of colorectal cancer screening
• A flexible, lighted tube with a camera is used to examine the entire colon
• Polyps can be removed during the procedure
• Recommended frequency: Every 10 years (if no polyps are found)
• Requires bowel preparation (a cleansing drink the day before) and sedation
• You will need someone to drive you home

CT Colonography (Virtual Colonoscopy)

• A CT scan creates detailed images of the colon
• No sedation required, but bowel preparation is still needed
• Recommended frequency: Every 5 years
• If polyps are found, a standard colonoscopy is needed to remove them

Flexible Sigmoidoscopy

• Examines only the lower portion of the colon
• Recommended frequency: Every 5 years, or every 10 years combined with annual FIT
• Less commonly used than colonoscopy in the U.S.

The best test is the one you will actually do. All of the above options are acceptable. Here is a simple way to think about it:

• Want the most thorough single test with the longest interval? → Colonoscopy every 10 years
• Prefer a non-invasive at-home test? → FIT every year or Cologuard every 1–3 years
• Want a middle ground? → CT colonography every 5 years

Talk with your doctor about which option fits your health history, preferences, and schedule.

Because colonoscopy is the most common and comprehensive screening method, here is a closer look at what the process involves.

The day before your colonoscopy, you will follow a bowel preparation — a liquid diet and a cleansing solution that empties your colon so the doctor can see clearly. This is the part most people find least comfortable, but newer prep formulas are more tolerable than older versions.

You will receive sedation (usually through an IV) so you are comfortable and relaxed. The gastroenterologist or surgeon inserts a colonoscope — a thin, flexible tube with a light and camera — through the rectum and guides it through the entire colon. The procedure typically takes 30–60 minutes.

If polyps are found, they are usually removed on the spot using small instruments passed through the colonoscope. You will not feel this.

You will rest in a recovery area for about 30–60 minutes as the sedation wears off. You will need a driver to take you home. Most people return to normal activities the next day.

• No polyps found: Return in 10 years
• Small, low-risk polyps removed: Return in 3–5 years
• Larger or higher-risk polyps removed: Return in 1–3 years (your doctor will advise)

Beyond age, several factors increase your risk of colorectal cancer:

• Family history: Having a first-degree relative (parent, sibling, child) with colorectal cancer roughly doubles your risk. If a relative was diagnosed before age 60, your risk is higher still.
• Personal history of polyps: Certain types of polyps (adenomas) increase future risk.
• Inflammatory bowel disease: Crohn's disease and ulcerative colitis increase risk, especially with long-standing disease.
• Type 2 diabetes: Associated with modestly increased risk.
• Obesity: Excess body weight, particularly around the abdomen, is a risk factor.
• Physical inactivity: Regular exercise is protective.
• Diet: High intake of red and processed meats is associated with increased risk; high fiber intake is protective.
• Smoking and heavy alcohol use: Both are associated with higher colorectal cancer risk.
• Race and ethnicity: Black Americans have the highest incidence and mortality rates of colorectal cancer of any racial or ethnic group in the U.S. and should discuss screening with their doctor.

Screening is designed to catch problems before symptoms appear. But if you experience any of the following, see your doctor promptly — do not wait for your next scheduled screening:

• Blood in the stool or rectal bleeding
• A persistent change in bowel habits (diarrhea, constipation, or narrowing of stool) lasting more than a few days
• Unexplained abdominal pain, cramping, or discomfort
• A feeling that your bowel does not empty completely
• Unexplained weight loss
• Fatigue or weakness without a clear cause

These symptoms can have many causes, most of them benign — but they always warrant evaluation.

Colorectal cancer is not inevitable. With regular screening starting at age 45, most cases can be prevented entirely or caught at a stage when treatment is most effective. The 5-year survival rate for localized colorectal cancer is over 90%. For cancer that has spread to distant organs, it drops to about 13%.

Screening is not just a test — it is an act of prevention.

At Manatee Primary Care, we help you understand your risk, choose the right screening test, and coordinate referrals when needed. Call us at (941) 867-9362 or request an appointment online. Do not put it off — your colon health is worth 30 minutes of your time.

This post is for educational purposes and does not replace personalized medical advice. Guidelines are based on USPSTF (2021), American Cancer Society (2018/2023 update), and ACG recommendations.