Screening options

Compare your screening options, side by side.

Several tests can screen for colorectal cancer. They differ in how they're done, how often they're needed, and what happens next. The best test is often the one you'll actually complete.

Last medically reviewed: June 2, 2026 Reflects the 2026 U.S. screening guideline update

One key thing to know: if a non-colonoscopy screening test is abnormal, a colonoscopy is generally needed to complete the screening process — ideally within about six months.

Colonoscopy

Typically every 10 years if normal (average risk)
Detect & prevent

What it is

A doctor uses a thin, flexible camera to examine the entire colon. Polyps can be found and removed during the same procedure, usually under sedation.

Pros

  • Examines the whole colon
  • Can remove polyps in one visit
  • Longest interval between tests

Limitations

  • Requires bowel prep
  • Sedation & a ride home
  • Small risk of complications
Finds cancerExcellent — the benchmark other tests are measured against
Finds polypsExcellent — can find and remove polyps in the same visit
Avoids false alarmsVery few; suspicious areas are checked on the spot
If abnormal: polyps are typically removed during the same procedure and sent for analysis.

FIT (Fecal Immunochemical Test)

Typically once a year
At-home stool test

What it is

An at-home test that checks a stool sample for hidden blood, which can be an early sign of polyps or cancer. No prep, no sedation.

Pros

  • Done at home, no prep
  • Non-invasive & low cost
  • No sedation or time off

Limitations

  • Must repeat every year
  • Doesn't remove polyps
  • Can miss some polyps
Finds cancerGood — catches roughly 7 in 10 cancers in a single test
Finds polypsLimited — misses most polyps (better at finding cancer than polyps)
Avoids false alarmsFew false alarms
If abnormal: a colonoscopy is needed to complete screening — preferably within about six months.

Stool DNA / RNA test

Typically every 3 years
At-home stool test

What it is

An at-home test that looks for both hidden blood and altered DNA/RNA markers shed by polyps or cancer cells in the stool. Examples include Cologuard Plus and ColoSense.

Pros

  • Done at home, no prep
  • Less frequent than FIT
  • No sedation or time off

Limitations

  • More false positives
  • Doesn't remove polyps
  • Higher cost than FIT
Finds cancerVery good — catches around 9 in 10 cancers
Finds polypsModerate — finds more polyps than FIT, but still misses many
Avoids false alarmsMore false alarms than FIT, meaning more follow-up colonoscopies
If abnormal: a colonoscopy is needed to complete screening — preferably within about six months.

CT colonography

Typically every 5 years
Imaging

What it is

A CT scan creates detailed 3-D images of the colon to look for polyps and other changes. Bowel prep is still needed, but no sedation.

Pros

  • Minimally invasive
  • No sedation needed
  • Views the whole colon

Limitations

  • Still requires bowel prep
  • Can't remove polyps
  • Not available everywhere
Finds cancerGood for larger polyps and cancers; less reliable for small ones
Finds polypsGood for larger polyps; misses smaller ones
Avoids false alarmsMay flag findings that need extra follow-up
If abnormal: a colonoscopy is needed to complete screening — preferably within about six months.

Blood-based screening

Interval varies — discuss with your clinician
Secondary option

What it is

A blood test (such as the FDA-approved Shield test) that looks for tumor DNA signals in the bloodstream. Best considered a secondary option for people unwilling or unable to complete a preferred screening test.

Pros

  • Simple blood draw
  • No prep or sedation
  • An option when others are declined

Limitations

  • Less sensitive for polyps
  • Not a first-choice test
  • Doesn't remove polyps
Finds cancerCatches most cancers (~8 in 10), but misses most precancerous polyps
Finds polypsPoor — misses most precancerous polyps, so it can’t prevent as well
Avoids false alarmsModerate — a normal result doesn’t rule out polyps
If abnormal: a colonoscopy is needed to complete screening — preferably within about six months.
Quick reference

How often is each test repeated?

Screening intervals for average-risk adults, side by side. The clock resets each time you complete a test with a normal result.

Test Repeat every What it's best at If abnormal
ColonoscopyDetect & prevent
10 years Finds & removes polyps in one visit Polyps removed during the same procedure
FITAt-home stool test
1 year Finding existing cancer Colonoscopy within ~6 months
Stool DNA / RNACologuard Plus, ColoSense
3 years Finding cancer; some polyps Colonoscopy within ~6 months
CT colonographyImaging
5 years Larger polyps & cancers Colonoscopy within ~6 months
Blood-basedSecondaryShield
Varies Finding cancer (not polyps) Colonoscopy within ~6 months

These intervals are for average-risk adults with normal results. If you've had polyps, a family history of colorectal cancer, IBD, or a hereditary syndrome, your interval is often shorter — your clinician will set the right schedule for you.

Two words you'll see: sensitivity & specificity

Tests are often described by these two numbers. Here's what they actually mean for you — no jargon.

Sensitivity

How well a test catches what's there. High sensitivity means it finds most cancers and polyps and rarely misses them. Low sensitivity means more can slip through.

Specificity

How well a test avoids false alarms. High specificity means a positive result is more likely to be real — so fewer people are sent for follow-up tests they didn't need.

No test is perfect, and the figures shown for each test are approximate, drawn from published studies and applied to a single test. Stool tests work best when repeated on schedule — yearly or every few years — which improves detection over time. Use this to start a conversation with your clinician, not to choose a test on your own.

Not sure which fits?

Let's narrow it down together.

Answer a few questions and we'll point you toward the right kind of conversation with your doctor.

Check My Risk