How I interpret a polyp finding
I separate three questions: what the polyp looks like, what the laboratory finds, and whether removal is complete. Most polyps are small and are not cancerous, but we remove them because some can slowly change into cancer if left in place. A small polyp may also be unrelated to the symptoms that led to your colonoscopy.
For follow-up in New Zealand, I consider the national polyp guidelines alongside your personal and family history, examination findings and previous reports to make the best overall recommendation for you. Bring reports from other services if you have them. The total number and types of polyps over several examinations can change the advice, including whether your family needs assessment.
Guidance behind this advice
Polyps can have different shapes
What is a bowel polyp?
A bowel polyp is a growth on the inner lining of the colon or rectum, which together make up the large bowel. Some grow on a stalk; others have a broad base or are almost flat.
Most polyps cause no symptoms. A small polyp found during your colonoscopy may not explain pain, bloating or a change in bowel habit. Please let me or your GP know if those symptoms continue.
Why was it removed?
Some types of polyp can develop into cancer over time. Removing them reduces that risk. It also allows the tissue to be examined in a laboratory.
Many polyps can be removed during the same colonoscopy. If a polyp needs a separate procedure or a different treatment, I will explain the options and the next step.
A biopsy takes a sample. It does not always remove the whole polyp. Your report should say whether a polyp was removed or only sampled.
How long does a polyp take to become cancer?
Most polyps never become cancer. For those that do, the change usually happens over many years. An adenoma can take 10 to 15 years to develop into cancer, but some polyps progress more quickly.
Some inherited conditions and polyposis syndromes are associated with higher-risk biology or with more polyps developing over time. Examples include Lynch syndrome and serrated polyposis syndrome. When these or other risk factors are present, surveillance is tailored to your personal and family history and the findings on each examination.
There is no reliable way to predict the time for an individual polyp. The type of polyp, its size and the cell changes affect the risk. Completely removing a precancerous polyp prevents that polyp from developing further. If removal was incomplete or the polyp was removed in pieces, a further check or treatment may be needed.
The 10 to 15 year estimate is not a reason to delay removal or your recommended follow-up. I use your colonoscopy findings and tissue results to decide when your next check should be.
How are polyps removed?
Polyp removal is called polypectomy. Small instruments pass through a channel inside the colonoscope, the flexible camera used to examine the bowel. They reach the polyp from inside the bowel, without a cut through the skin.
I choose the approach according to the polyp’s size, shape, position and appearance, and your health and medicines. The diagram explains common techniques. Some complex polyps need advanced endoscopic treatment or surgery.
Polyp removal leaves a wound in the bowel lining. After a small polyp is removed, this usually heals quickly. Larger removal sites can take longer. Follow the discharge instructions I give you about medicines, activity and travel.
Significant bleeding is uncommon after small polyps are removed, particularly with a cold snare. The risk is higher with larger polyps or blood-thinning medicines. A hole in the bowel wall (perforation) is rare. I will discuss the risks for your procedure. The advice below explains when to get help.
What does the laboratory check?
A specialist doctor called a pathologist examines the removed tissue under a microscope. The report identifies the polyp type and checks for abnormal cells or cancer. This is often called the histology or pathology result.
I combine this result with the colonoscopy findings when advising you about the next step. Sometimes more treatment is needed to make sure a polyp has been completely removed.
Words you may see in your report
Open a term for a short explanation.
Adenoma
A common type of polyp that can develop into cancer. An adenoma is not itself an invasive cancer. Tubular, tubulovillous and villous describe patterns seen under the microscope. Tubulovillous and villous patterns are higher-risk changes, but they do not indicate cancer. These findings help guide follow-up.
Sessile serrated lesion (SSL)
Another type of polyp that can develop into cancer. It is often flat or broad-based. You may also see the older terms sessile serrated polyp or sessile serrated adenoma. A traditional serrated adenoma is a less common related type. In some people, a large number of SSLs forms part of a familial condition called serrated polyposis syndrome, which needs tailored follow-up.
Hyperplastic polyp
Small hyperplastic polyps, especially in the lower bowel, usually have very little cancer risk. Larger ones, or many serrated polyps, may still be relevant for cancer prevention. I consider the full pattern of findings.
Dysplasia and high-grade dysplasia
Dysplasia means abnormal changes in the cells. High-grade dysplasia describes more advanced changes, but is not the same as invasive cancer. Complete removal and appropriate follow-up are important. I will explain what the findings mean for you.
What if the report says cancer was found?
I will discuss the result and treatment options with you. Some very early cancers can be treated by removing the polyp. Others need surgery or further assessment. The decision depends on the detailed pathology and whether removal was complete.
Will I need another colonoscopy?
Not everyone needs the same follow-up. When recommending your next check, I consider:
- The type, size and number of polyps, including polyps removed previously.
- Whether there were more advanced cell changes, and whether removal was complete.
- How clearly the bowel could be seen and whether the examination was complete.
- Your family history, age, health and preferences.
Some people can return to routine bowel screening when eligible. Others need a follow-up colonoscopy, called surveillance. A large polyp removed in pieces may need an earlier check of the removal site. This is different from a later examination to look for new polyps.
I will document your recommended follow-up in your endoscopy report and/or histology report once the tissue results are available. A negative FIT stool test does not replace a colonoscopy that has been recommended for polyp follow-up.
Does this affect my family?
One small polyp does not by itself mean your relatives need colonoscopy. A large number of polyps, polyps at a young age, or a family history of bowel cancer may change the advice. Please let me know which relatives were affected and their ages at diagnosis. We can discuss whether your family needs a separate screening plan.
What should I do now?
- Keep your endoscopy report and histology report or results letter. These will record your recommended follow-up.
- Check who will tell you the results and when to expect them. Contact our team if a result we are arranging has not arrived when expected. If another service arranged your test, contact that service or your GP.
- Ask whether all polyps were removed, whether further treatment is needed, and when your next check is due.
- Follow your discharge instructions about medicines, activity and travel. If you take blood thinners, follow the documented medication plan. If you are unsure, call our endoscopy team before changing a dose.
After removal: when to get help
Mild bloating can occur after colonoscopy. Significant bleeding is uncommon after small polyps are removed with modern techniques, particularly a cold snare. The risk is higher with larger polyps and in people taking blood thinners. Bleeding can start several days after removal, including during the following two weeks.
If you take blood thinners
Your medication plan should be documented in your endoscopy report or discharge instructions. It should say whether each blood thinner needs to be withheld and, if so, when to take the last dose and when to restart it. Some medicines can be continued. If the instructions are missing or you are unsure, give our endoscopy team a call before changing a dose.
When to get help
Seek urgent medical assessment for heavy or ongoing bleeding, blood clots, black tarry stools, severe or worsening abdominal pain, fever, persistent vomiting, or feeling faint or very unwell. Call our endoscopy team immediately or go to an emergency department.
Call 111 for an ambulance if you collapse, have heavy bleeding with faintness, or are too unwell to travel safely. Do not wait for a routine appointment or an email reply.
Three things to remember
- A polyp is a growth on the inside lining of the bowel. Most are not cancer.
- The laboratory result helps identify the type of polyp and whether further treatment is needed.
- Your recommended follow-up will be documented in your endoscopy report and/or histology report once the tissue results are available.
Sources and further reading
- American Cancer Society: how screening prevents bowel cancer
- BSG/ESGE: endoscopy and blood-thinning medicines (2021)
- ESGE: polyp removal and EMR guideline (2024)
- Te Aho o Te Kahu: NZ polyp surveillance guidance (2024)
- NHS: bowel polyps
- American Cancer Society: understanding a polyp pathology report
- Endoscopy Auckland: colonoscopy and aftercare
- North Tees NHS: aftercare following polyp removal
Clinical source check: 14 October 2026.
This is general information. Your results letter and discharge instructions contain the advice for your own care.