Understanding polyps
In short
A polyp is a small growth on the inner lining of the colon. Most polyps are not cancer. Some kinds, given enough time, can become cancer — which is the reason coloscopy looks for them and removes them when they are found. Hearing that polyps were taken out is, in most cases, a sign that the test did its job.
What this page covers
What a polyp is, why polyps are removed during a coloscopy rather than later, what the report tends to say about size and shape, and what their presence means for your future risk and your follow-up.
- The basic biology — what is being removed, and from where
- How polyps are described on the procedure note
- The relationship between polyps and colorectal cancer
- What "complete" removal means and why it matters
- How findings shape the next coloscopy
What a polyp is
The colon is lined by a single layer of cells that turn over rapidly — older cells are shed into the stool and replaced by new ones from below. When that turnover gets out of step, a small mound of cells builds up on the lining. That mound is a polyp. It can be the size of a sesame seed or, less often, the size of a large grape. It sits on the inner surface of the bowel and, in early stages, does not cause symptoms.
Polyps are common. The proportion of average-risk adults found to have at least one polyp at screening coloscopy is high enough that the result is unsurprising rather than alarming. The fact that they exist is not, by itself, a sign of disease. What matters is what kind of polyp it is, how big, how many, and whether it could be removed completely.
Why polyps are removed during the test
It is more efficient and safer to remove a polyp the first time it is seen than to leave it and return for a separate procedure. Most polyps are removed using one of two techniques. Cold snare polypectomy uses a thin wire loop to lasso the polyp at its base and slice it off without electric current; this is the standard for small polyps. Hot snare polypectomy applies a brief electric current as the loop closes; this is used for larger or stalked polyps where bleeding control matters more. For larger flat polyps, an endoscopic mucosal resection (EMR) lifts the polyp away from deeper tissue with an injected fluid cushion and removes it in one or several pieces; endoscopic submucosal dissection (ESD) is a more advanced technique used at specialist centres for selected lesions.
The polyp is then retrieved through the scope and sent to the laboratory. There, a pathologist slices the tissue thinly, stains it, and examines it under a microscope. The pathology report describes what the polyp was made of, whether the borders looked clean, and whether any abnormal-looking cells were found. That report is the source of nearly every recommendation that follows.
How the procedure note describes polyps
Reading the endoscopist's note can be disorienting if you are not used to the language. A typical entry might read: a 7 mm sessile polyp in the sigmoid colon, removed by cold snare, retrieved. Each part of that sentence carries information.
Size is reported in millimetres. Endoscopists estimate this against the open jaws of an instrument or the snare wire. Larger polyps — especially those above 10 mm — receive more attention because the chance of finding more advanced features inside them rises with size.
Shape matters because it changes how the polyp is removed and, sometimes, what it is likely to be made of. Pedunculated means stalked, like a mushroom — the polyp sits on a narrow neck of tissue. Sessile means flat-based, sitting directly on the bowel wall like a button. Flat or depressed polyps are harder to see and harder to remove cleanly.
Location is described by segment of colon — caecum, ascending, transverse, descending, sigmoid, rectum — because findings in the right colon (caecum, ascending, often transverse) and left colon (descending, sigmoid, rectum) carry slightly different implications.
Retrieval simply means the polyp was caught and brought back. Very small polyps occasionally cannot be retrieved; in that case the endoscopist documents the appearance.
Polyps and colorectal cancer — the connection
Most colorectal cancers begin as a polyp of a particular kind, grow over years, and only later acquire the changes that make them invasive. This is the reason a single coloscopy with polyp removal can substantially lower the chance of dying of colorectal cancer in the years that follow — large studies from the United States, Europe, and elsewhere support this consistently. The pathway is gradual; it is also not inevitable. Many polyps would never have caused harm even if left in place. The trouble is that no one can tell which is which while looking at them, so the safer path is to remove what is there and have it examined.
Two pathways are recognised. The conventional adenoma–carcinoma sequence begins with an adenoma (a polyp made of glandular tissue with abnormal but not cancerous cells) and progresses through grades of dysplasia (disorder of the cells when seen under the microscope) before becoming cancer. The serrated pathway begins with sessile serrated lesions — flat, often pale polyps that sit in the right colon and were under-recognised for years — and follows a different molecular route to the same destination.
What "complete removal" means and why it matters
A clean resection — the polyp lifted off in one piece with the base visible to the endoscopist and the edges intact under the microscope — is the goal. The pathology report may describe en bloc removal (taken out as a single specimen), piecemeal removal (taken in fragments, common for larger flat polyps), or note fragmentation of the specimen. The margins are the cut edges; clear margins mean the pathologist did not see polyp tissue running off the edge of the slide. When margins cannot be assessed, or when the polyp came out in many small pieces, your clinician will often suggest a closer-than-usual look back at the site.
None of this language means cancer was found. It means the team is being careful about whether anything could have been left behind to grow back.
How findings shape the next coloscopy
The number of polyps, their size, their histology, their location, and how cleanly they were removed all feed into a recommendation about when to come back. A single small polyp of a low-risk type usually points to a long interval before the next test. A large polyp, several polyps, or a polyp with concerning features under the microscope shortens the interval, sometimes substantially. Sessile serrated lesions are taken seriously because they were once missed.
Your follow-up plan should arrive in writing, either in your discharge paperwork or in a letter or portal message after the pathology returns. If it does not, ask. See surveillance intervals for typical ranges.
What to ask your clinician
- How many polyps were removed, where were they, and how big were they?
- Were any polyps removed in pieces rather than in one piece, and does that change the plan?
- What did the pathology show — adenoma, sessile serrated lesion, hyperplastic, or something else?
- Was there any high-grade dysplasia, villous component, or invasive feature mentioned?
- Were the margins clear?
- When should I have my next coloscopy, and what is that interval based on?
- Is there anything about my findings that should prompt a conversation about family screening?
Common worries, briefly addressed
Does having polyps mean I will get cancer?
No. Most people who have polyps removed never develop colorectal cancer. The removal itself is part of the reason. Polyps are common; the pathway from polyp to cancer is slow, possible, and often interrupted by exactly the test you have had.
Did I cause the polyps?
Diet, smoking, alcohol, and weight all modestly influence risk over a lifetime, but polyps also occur in people who do everything within their control. Family history and inherited factors play a larger role than is sometimes realised. There is rarely a single cause to identify.
Can polyps grow back in the same place?
It can happen, particularly when a large polyp was removed piecemeal. This is why a closer look at the resection site is sometimes recommended within months rather than years.
I have a strong family history. Does that change anything?
It can. Tell the clinician who manages your follow-up about any first-degree relatives (parents, siblings, children) with colorectal cancer or advanced polyps, and at what age they were diagnosed. See family history and genetics.
Sources
- U.S. Multi-Society Task Force on Colorectal Cancer — recommendations for follow-up after coloscopy and polypectomy
- European Society of Gastrointestinal Endoscopy — post-polypectomy coloscopy surveillance guideline
- American College of Gastroenterology — clinical guideline on colorectal cancer screening
- British Society of Gastroenterology — post-polypectomy and post-colorectal cancer resection surveillance guidelines
- American Cancer Society — information on colorectal polyps and cancer
- National Institute for Health and Care Excellence — colorectal cancer guideline