Colorectal Cancer Screening: 9 Questions Comparing Colonoscopy and Stool Tests
When it comes to Colorectal Cancer (CRC) screening, it might seem confusing since there are several different tests available – and each one is slightly different. During CRC Awareness Month, let’s discuss some key differences between stool tests, like Cologuard, blood tests and colonoscopy. We will cover which test is appropriate, based on your risk factors. Here are some common questions people ask about CRC screenings.
1. Is a stool test as good as a colonoscopy?
If the goal is cancer prevention, then the clinicians here at Gastroenterology of the Rockies would encourage patients to choose colonoscopy screening over stool tests. Why? Because during a colonoscopy screening, your gastroenterologist can see your entire GI tract and remove pre-cancerous polyps—that could eventually grow into an early-stage cancer.
Unlike other tests, colonoscopy can help potentially prevent colon cancer, whereas stool tests find cancer after it starts to grow.
2. What if you get a positive test result from stool test?
When a patient receives a positive result from stool tests, their next step requires a colonoscopy to confirm the findings.
3. Aren’t all colorectal cancer tests the same?
No, not all CRC tests are created equal. The FDA-approved blood test for CRC may be considered an option when patients cannot screen with colonoscopy, according to a position statement from American Society of Gastrointestinal Endoscopy, (ASGE).
“ASGE does not recommend the blood test as a first line screening tool,” reported in their position statement.
ASGE acknowledges that underserved segments of the population may not have access to healthcare screenings like colonoscopy. ASGE suggests that better healthcare policies could help improve access to care by addressing healthcare disparities in underserved patient populations.
Healthcare Disparities
Here are a few common barriers to care.
4. Do stool tests replace colonoscopy?
No. If a patient decides to take a stool test, this is considered a first step during the patient evaluation for colon cancer. If the test is positive, a colonoscopy is needed to confirm the result. Your doctor will discuss necessary steps once they review the test results.
5. Can I do a stool test if I have symptoms like bleeding or pain?
We realize how many people Google “symptoms + test options” to help answer the question about whether stool tests are appropriate for them.
“It is not common to see blood on toilet paper when wiping after using the bathroom or even not using the bathroom,” Dr Clarke said.
“I would say in a young person 20 years ago, we would attribute this to internal hemorrhoids. But with the rising incidence of colorectal cancer in younger patients, I would not dismiss this symptom of rectal bleeding.”
If you’re seeing toilet paper with blood or blood dripping into the toilet, Dr. Clarke said it’s a good idea to have a doctor evaluate your unique symptoms. Talking to a doctor can help determine appropriate next steps, including whether it makes sense to schedule a colonoscopy screening.
6. Can stool tests detect polyps?
Yes. Stool tests can detect large advanced polyps. However, if you’re focused on early detection and prevention measures, it’s important to understand that stool tests aren’t designed to prevent colon cancer.
By the time a stool test indicates a positive result and then confirmed with colonoscopy, patients have lost a critical window of time, in terms of cancer prevention.
“Most colon cancers can be prevented by undergoing screening colonoscopy and removing polyps. And additionally, when colon cancer is detected during screening, it is more likely to be found at an early and often curable stage,” said Nathan Susnow, MD, gastroenterologist with Gastroenterology of the Rockies.
“Awareness and timely screening can make a measurable difference in your health and peace of mind,” he added.
- Colonoscopy offers the highest sensitivity rate for colon cancer screening, compared to other tests available, according to the American College of Gastroenterology.
Reliability matters, that’s why our board-certified gastroenterologists highly recommend colonoscopy over stool tests. Colonoscopy has a 95 percent detection rate for finding advanced colon polyps, a finding published October 2025, in Cureus Journal of Medical Science.
- Various stool tests report advanced polyp detection rates around 30 percent and 42 percent, depending on various brands.
Visit our colon cancer screening page to see these graphs and charts.
7. What does a false positive stool test really mean?
Let’s clarify what is meant by false positives with stool tests. False positives indicate that a disease or condition is reported as present—even though the disease is not present, when confirmed by a secondary test.
- Also, stool tests have repeatedly given false positives. For example, blood from a hemorrhoid can throw a false positive in stool tests, Dr. Clarke said.
CRC Health Trends
[3] Source: JAMA-March 2026
8. What is the difference between Cologuard and FIT?
| Cologuard | FIT |
| Positive test result indicates need for a colonoscopy to confirm results and possibly remove polyps. | Positive test result indicates need for a colonoscopy to confirm results and possibly remove polyps |
| Detects advanced colon polyps with 42% accuracy | Detects advanced colon polyps with 30% accuracy |
| Not FDA-approved for high-risk patients. | Not FDA-approved for high-risk patients. |
| Recommended every 3 years |
Recommended annually |
9. What’s the best colon cancer screening test for me?
The “best test question” is a good one to ask since there are a few options. For some people, convenience will affect their decision. But the answer truly depends on several factors related to your personal health history. Another consideration is whether you have a family history of colon polyps, colon cancer or IBD. People with these risk factors are not candidates for stool tests.
When asking yourself the question, ‘Which test should I choose?’ – a good starting point is to assess whether you’re of average or high risk. Talk to your doctor or GI specialist to get the conversation started. Sharing your medical history helps your doctor help you.
If you have questions or concerns about colon cancer and would like to set up a consultation, call our office at 303-604-5000.
Written by Elise Oberliesen, digital marketing specialist; medical review given by Emily Marshall, PA-C.
March 12, 2026
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References
[1]University of Southern California, 6 examples of health disparities https://priceschool.usc.edu/price-blog/6-examples-of-health-disparities-and-potential-solutions/
[2] Colorado Department of Health & Environment. Progress and next steps to advance health equity for older adults in Colorado, https://cdphe.colorado.gov/ohe
[3] JAMA, Leading Cancer Deaths in People Younger Than 50 Years, March 2026, https://jamanetwork.com/journals/jama/article-abstract/2844189