Colon Cancer Screening: What to Expect, When to Start, and Why It Matters
Talking about colon cancer screening (also called colorectal cancer screening) can feel awkward. The good news? Screening is one of the best ways to prevent colon cancer or find it early, before you feel sick.
Here’s a simple guide to what colon cancer screening is, when to start, and what to expect.
What Is Colon Cancer Screening?
Colon cancer, also called colorectal cancer, starts in the colon or rectum. It often begins as a small growth called a polyp. Over time, some polyps can turn into cancer.
Colorectal cancer is one of the most common and serious cancers in our state. In Oregon, it is the fourth most diagnosed cancer and the fourth leading cause of cancer death, according to the Oregon Health Authority (OHA).
Colon cancer screening looks for polyps and early cancer before you have symptoms.
When cancer is found early, it’s much easier to treat. In many cases, screening can even prevent cancer by removing polyps before they become dangerous.
When Should I Start Colon Cancer Screening?
For most people at average risk, screening starts at age 45.
You may need to start earlier if you have:
- A close family member with colorectal cancer
- Certain genetic conditions
- Inflammatory bowel disease (such as Crohn’s disease or ulcerative colitis)
Not sure what applies to you? Your NHC care team can help you decide.
Do I Need Symptoms to Get Screened?
No, and that’s the whole point.
Colon cancer screening is for people who feel fine.
If you wait for symptoms, the cancer may already be harder to treat.
What Colon Cancer Screening Options Are There?
Most people have two main options: at-home stool tests or a colonoscopy.
Option 1: At-Home Stool Tests
These tests check your stool for hidden blood (and sometimes DNA changes).
You collect a sample at home and send it to a lab.
Common options include:
- FIT (fecal immunochemical test) – usually done every year
- Stool DNA test – usually done every 3 years
These tests are convenient and non-invasive.
Important: If a stool test is abnormal, the next step is a colonoscopy to find out why.
Option 2: Colonoscopy
A colonoscopy allows a specialist to look inside your colon using a small camera.
Most people are sedated, so you are relaxed and comfortable during the procedure.
One major benefit: A colonoscopy can find and remove polyps during the same visit. That’s one reason it’s considered the most reliable colon cancer screening test.
If your results are normal, many people only need one every 10 years.
What Should I Expect With a Colonoscopy?
For most people, the prep is the hardest part, not the procedure itself.
In general:
- You’ll follow food instructions for a few days before
- You’ll drink a prep solution to clean out your colon
- The procedure takes about 30–60 minutes
- You’ll need someone to drive you home because sedation is used
Serious risks are rare, but can include bleeding or a tear in the colon wall.
Your care team will explain every step so you know what to expect.
Related: What's a Care Team?
Is Colon Cancer Screening Covered by Insurance?
For most people, yes. Colon cancer screening is a covered preventive service for most adults on the Oregon Health Plan (OHP). That means screening is often available at low or no cost.
Many Medicare and private insurance plans also cover colon cancer screening when it’s done on schedule and before symptoms start.
If you don’t have insurance, you still have options. NHC offers a Sliding Fee Discount Program for eligible patients to help make preventive care more affordable.
If cost is a concern, talk with your care team. We can help you understand what’s covered and what makes the most sense for you.
What Happens If Something Abnormal Is Found?
Take a breath. “Abnormal” does not always mean cancer.
If an at-home test is abnormal, the next step is a colonoscopy, often recommended within about 60 days.
If a colonoscopy finds a polyp, it can often be removed right away and sent to a lab for testing. Final lab results usually take about a week.
Your care team will walk you through the next steps, one piece at a time.
How NHC Can Help
If you’re 45 or older (or younger than 45 and have a higher risk), we can help you:
- Figure out when to start colon cancer screening
- Choose the screening option that fits your life
- Understand your results
- Plan next steps if needed
Screening isn’t about fear. It’s about staying healthy for the people who count on you.
If you’re due for screening, talk with your primary care provider or schedule a visit with our team.
Common Questions About Colon Cancer Screening
Does colon cancer screening hurt?
Most people do not feel pain during a colonoscopy because sedation is used. Stool tests are done at home and are not painful.
Can I do colon cancer screening at home?
Yes. FIT and stool DNA tests can be done at home. If results are abnormal, you’ll need a colonoscopy.
What if I’m younger than 45?
If you have a family history or certain health conditions, your provider may recommend starting earlier.
How often do I need colon cancer screening?
It depends on the test. Colonoscopy is often performed every 10 years. FIT is yearly. Stool DNA testing is usually performed every 3 years.
The information in this article is for educational purposes only and is not a substitute for medical advice, diagnosis, or treatment. Please talk with your care team about questions or concerns related to your health.
Sources
Cleveland Clinic. Colorectal Cancer Screening. Last updated June 24, 2025.
https://my.clevelandclinic.org/health/diagnostics/colorectal-cancer-screening
National Cancer Institute (NCI). Colorectal Cancer Screening (PDQ®)–Patient Version.
https://www.cancer.gov/types/colorectal/patient/colorectal-screening-pdq
American Cancer Society. Colorectal Cancer Screening Tests.
https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html
Mayo Clinic. Colon cancer screening: Weighing the options. January 22, 2025.
https://www.mayoclinic.org/diseases-conditions/colon-cancer/in-depth/colon-cancer-screening/art-20046825
The Cancer You Can Prevent. Oregon Colorectal Cancer Data.
https://www.thecanceryoucanprevent.org/data
This article was reviewed by Samantha Abbott, FNP, a Family Nurse Practitioner at NHC Milwaukie Medical Clinic. Samantha earned her Master of Science in Nursing from Vanderbilt University and her Bachelor of Arts from Portland State University. She has clinical experience in primary care, urgent care, pediatric primary care, and in-home pediatric asthma services. At NHC, she provides primary care for patients of all ages and backgrounds, with a clinical interest in Hepatitis C treatment and whole-person care.