Why Colorectal Cancer Screening Matters
Colorectal cancer begins in the colon or rectum and often develops gradually from abnormal growths called polyps. These polyps may be present for years without causing noticeable symptoms.
Screening can help identify certain polyps before they become cancer and can also detect colorectal cancer at an earlier stage, when treatment may be more effective.
When Should You Start Screening?
For most adults at average risk, colorectal cancer screening should begin at age 45 and continue regularly through age 75.
For adults between ages 76 and 85, the decision to continue screening is more individualized and should be discussed with a healthcare provider.
Some people may need to begin screening earlier because of their personal medical history, family history, or other risk factors.
Your Colorectal Cancer Screening Options
Many people assume colorectal cancer screening always means having a colonoscopy. While colonoscopy is an important screening method, several options are available for adults at average risk.
- FIT (fecal immunochemical test) — an at-home stool test generally completed once a year
- Stool DNA testing — an at-home test that looks for certain abnormal changes and hidden blood in the stool
- Colonoscopy — examines the entire colon and allows many polyps to be removed during the procedure
- CT colonography — an imaging test sometimes called a virtual colonoscopy
- Flexible sigmoidoscopy — examines the rectum and lower portion of the colon
Your healthcare provider can help determine which screening method and schedule are most appropriate for you.
The best screening test is one that is appropriate for your health history and that you are willing to complete on schedule.
What Happens If a Screening Test Is Abnormal?
An abnormal stool-based or other non-colonoscopy screening result does not automatically mean that you have colorectal cancer.
However, an abnormal result usually requires follow-up with a colonoscopy so your physician can examine the colon directly and determine the cause.
Completing recommended follow-up testing is an important part of the screening process.
Who May Need Earlier Screening?
Age 45 is the usual starting point for adults at average risk, but certain patients may need to begin sooner or be screened more frequently.
Talk with your healthcare provider if you have:
- A family history of colorectal cancer or advanced polyps
- A personal history of colorectal cancer or certain polyps
- Inflammatory bowel disease — including Crohn's disease or ulcerative colitis
- A hereditary cancer syndrome — such as Lynch syndrome or familial adenomatous polyposis
- A history of radiation treatment to the abdomen or pelvis
Your family history is especially important. Tell your healthcare provider if a close relative has had colorectal cancer or significant colon polyps, particularly if they were diagnosed at a younger age.
Symptoms You Shouldn't Ignore
Screening is intended for people who do not have symptoms. If symptoms are already present, your healthcare provider may recommend diagnostic testing instead.
Possible warning signs can include:
- Blood in or on your stool
- A persistent change in bowel habits
- Persistent abdominal pain or cramping
- A feeling that your bowel does not completely empty
- Unexplained weight loss
- Unexplained iron-deficiency anemia
These symptoms can have many causes and do not necessarily mean that you have cancer. However, persistent or unexplained changes should be evaluated by a healthcare provider.
Can Colorectal Cancer Develop Without Symptoms?
Yes. Colorectal cancer and precancerous polyps may not cause noticeable symptoms in their early stages.
This is why waiting until something feels wrong is not a good screening strategy. Preventive screening is designed to identify changes before symptoms appear.
Feeling healthy does not mean screening isn't necessary. Preventive care is most valuable before symptoms develop.
Reducing Your Risk
Some colorectal cancer risk factors, including age, genetics, and family history, cannot be changed. Healthy lifestyle choices can still support your overall health and may help lower your risk.
- Stay physically active
- Work toward maintaining a healthy weight
- Avoid tobacco use
- Limit alcohol consumption
- Know your family medical history
- Stay current with recommended preventive screenings
Don't Put Off Your Screening
If you're 45 or older and haven't started colorectal cancer screening, consider discussing your options at your next healthcare visit. If you're younger but have a significant personal or family history, ask whether earlier screening may be appropriate.
With several screening options available, your healthcare provider can help you choose an approach based on your health history, individual risk, and preferences.