Skip to content
Clinician reference tool

Colonoscopy surveillance interval

Enter the polyps removed and see the surveillance interval the guideline sets, with the rule and its source.

Canada has no maintained national post-polypectomy guideline; the provinces differ.

Baseline colonoscopy only

Not for intervals after a surveillance colonoscopy.

Outside the guidelines

Tick if any apply.

Bowel prep · Boston scale
Right colon
Transverse
Left colon
Total 9 / 9 · Adequate
Polyps removed
Lesion type
Awaiting histology
Interval depends on the result
The interval each possible histology for the pending lesion would give. Confirm once histology returns.
PrevalenceHistopathologyGuideline interval
~45–60%Tubular adenoma5 years
~20–30%Hyperplastic10 years
~5–15%Tubulovillous / villous3 years
~1–8%Sessile serrated5 years
<1%Traditional serrated3 years

Prevalence source ↗

Canada · Ontario

How ColonCancerCheck sets the colonoscopy surveillance interval

Cancer Care Ontario's ColonCancerCheck (CCC) recommendations set the surveillance interval from the size and histology of the most advanced lesion found, and assume a high-quality colonoscopy that reached the cecum with adequate bowel preparation. Lower-risk findings return the patient to fecal immunochemical test (FIT) stool screening rather than a repeat colonoscopy: no polyps or rectosigmoid hyperplastic polyps go to FIT in 10 years, and low risk adenomas to FIT in 5 years. Higher-risk adenomas, serrated lesions, and piecemeal resections stay on colonoscopy surveillance, from 3 years down to a 6-month check of the resection site.

Finding at the baseline colonoscopySurveillance interval
No polyps, or hyperplastic polyps in the rectum or sigmoidFIT in 10 years
Low risk adenomas: 1 to 2 tubular adenomas under 10 mm with no high-grade dysplasiaFIT in 5 years
Sessile serrated adenoma under 10 mm without dysplasiaColonoscopy in 5 years
High risk (advanced) adenomas: a tubular adenoma 10 mm or larger, 3 or more adenomas, villous histology, or high-grade dysplasiaColonoscopy in 3 years
Sessile serrated adenoma 10 mm or larger, sessile serrated adenoma with dysplasia, or traditional serrated adenomaColonoscopy in 3 years
Large sessile polyp removed piecemealColonoscopy to check the polypectomy site within 6 months
Serrated polyposis syndromeColonoscopy in 1 year
More than 10 adenomasClearing colonoscopy within 1 year

Ontario returns lower-risk patients to stool-based FIT screening instead of a surveillance colonoscopy: 1 to 2 small tubular adenomas get a FIT in 5 years, where the US schedules a colonoscopy at 7 to 10 years.

Source: ColonCancerCheck / Cancer Care Ontario — Recommendations for Post-Polypectomy Surveillance. This is the baseline colonoscopy table; enter specific findings in the calculator above for the rule and its exact wording.

For common questions and the source behind each rule across all the guidelines, see the colonoscopy surveillance guideline reference.

Reference tool for health professionals. Not medical advice, not a medical device, and does not make or replace a clinical decision. The calculation runs in your browser; the findings you enter are not transmitted or stored. The Aescia clinical team reviews this tool periodically against the source guidelines and updates it when they change, but guidelines are revised without notice; verify against the current version before acting. If you notice an error, tell us at contact@aesciahealth.com.

Aescia builds pre-procedure and surveillance-recall software for endoscopy clinics. See what we do.