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.
No lesion at this exam — scored as a normal colonoscopy.
A normal colonoscopy.
Show exact guideline wording
No polyps / Hyperplastic polyp(s) in rectum or sigmoid | FIT* | 10 years
Table, "Initial colonoscopy" half, row 1, page 1
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 colonoscopy | Surveillance interval |
|---|---|
| No polyps, or hyperplastic polyps in the rectum or sigmoid | FIT in 10 years |
| Low risk adenomas: 1 to 2 tubular adenomas under 10 mm with no high-grade dysplasia | FIT in 5 years |
| Sessile serrated adenoma under 10 mm without dysplasia | Colonoscopy in 5 years |
| High risk (advanced) adenomas: a tubular adenoma 10 mm or larger, 3 or more adenomas, villous histology, or high-grade dysplasia | Colonoscopy in 3 years |
| Sessile serrated adenoma 10 mm or larger, sessile serrated adenoma with dysplasia, or traditional serrated adenoma | Colonoscopy in 3 years |
| Large sessile polyp removed piecemeal | Colonoscopy to check the polypectomy site within 6 months |
| Serrated polyposis syndrome | Colonoscopy in 1 year |
| More than 10 adenomas | Clearing 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.
After a surveillance colonoscopy
ColonCancerCheck keys the subsequent interval to the original finding. A high-risk-adenoma baseline stays on 5-year colonoscopy after a clean, hyperplastic, or low-risk-adenoma exam, or moves to 3 years if a high-risk adenoma recurs. It does not return the patient to the faecal test.
The calculator gives a timeframe wherever the guideline or the screening programme sets one, and labels anything the guideline does not itself specify.
Age, stopping, and risk factors
Age. ColonCancerCheck prints no age cap for surveillance.
Risk factors. A hereditary syndrome, inflammatory bowel disease, or a personal or family history of colorectal cancer is followed under a separate pathway.
Colonoscopy surveillance intervals: quick answers
How soon should a colonoscopy be repeated after polypectomy under Ontario (ColonCancerCheck)?
It depends on the most advanced lesion. Cancer Care Ontario's ColonCancerCheck (CCC) recommendations set a colonoscopy at 3 years for high-risk adenomas, 5 years for a small sessile serrated lesion, or 6 months after piecemeal removal of a large sessile polyp. Lower-risk findings return to fecal immunochemical test (FIT) screening instead.
What is the surveillance interval for 1 to 2 small tubular adenomas in Ontario?
For 1 to 2 tubular adenomas under 10 mm with no high-grade dysplasia, ColonCancerCheck (CCC) does not schedule a surveillance colonoscopy. The patient returns to stool-based screening with a fecal immunochemical test (FIT) in 5 years, rather than the colonoscopy at 7 to 10 years used by the US guidance.
When should a repeat colonoscopy be done for advanced adenomas under ColonCancerCheck?
For high-risk (advanced) adenomas, ColonCancerCheck (CCC) recommends a repeat colonoscopy in 3 years. This category covers a tubular adenoma 10 mm or larger, 3 or more adenomas, villous histology, or high-grade dysplasia. Any single one of these features places the finding in the 3-year interval.
What is the follow-up interval for sessile serrated lesions in Ontario?
It depends on size and histology. A sessile serrated adenoma under 10 mm without dysplasia is followed by colonoscopy in 5 years. A sessile serrated adenoma 10 mm or larger, one with dysplasia, or a traditional serrated adenoma moves to colonoscopy in 3 years under ColonCancerCheck (CCC).
When should the site be rechecked after piecemeal removal of a large sessile polyp?
When a large sessile polyp is removed piecemeal, ColonCancerCheck (CCC) recommends a colonoscopy to check the removal site within 6 months. This early look is separate from the interval set by the lesion's histology and confirms the site is clear of residual tissue before returning to a routine surveillance schedule.
When does a patient return to FIT screening instead of surveillance colonoscopy in Ontario?
Lower-risk findings return to fecal immunochemical test (FIT) screening rather than a repeat colonoscopy. A normal exam, or hyperplastic polyps in the rectum or sigmoid, goes to FIT in 10 years. One to two small tubular adenomas without high-grade dysplasia go to FIT in 5 years under ColonCancerCheck (CCC).
What is the interval for serrated polyposis syndrome or more than 10 adenomas in Ontario?
Both carry a 1-year interval. ColonCancerCheck (CCC) recommends a colonoscopy in 1 year for serrated polyposis syndrome. When more than 10 adenomas are found, it recommends a clearing colonoscopy within 1 year to ensure all lesions are removed before setting the next surveillance interval.
For the guideline sources and side-by-side interval tables 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.
Last reviewed against the source guidelines on 14 July 2026.
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