How are polyps removed?

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Choose a part of the procedure. The technique depends on the polyp; not every step is needed for everyone.

Removing a polyp with a snare

A thin wire loop, called a snare, passes through the colonoscope. It closes around the polyp to cut it away. A cold snare cuts without heat and is commonly used for small polyps. A hot snare uses an electrical current for selected polyps.

Simplified illustrations, not to scale. They show the inside surface and layers of the bowel wall; they are not a guide to performing the procedure.

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Removing a polyp with a snare

A fluid cushion can help with removal

For some larger or flatter polyps, fluid is injected underneath to lift the polyp away from the deeper muscle. A snare then removes the raised tissue. This is one approach to endoscopic mucosal resection (EMR). Not every polyp needs an injection.

Checking the removal site

After removal, I check the area for remaining polyp tissue and bleeding. If needed, I can place a small metal clip through the colonoscope to stop bleeding or bring the wound edges together. This is called a through-the-scope (TTS) haemostatic clip. Its jaws grip the tissue and the clip stays in place when the delivery device is withdrawn. These clips are extremely small, generally fall out on their own over days to weeks, usually without you noticing, and are safe for MRI. Clips are not needed for every polyp. A larger polyp removed in pieces may need an earlier check of the site.

The removed tissue goes to the laboratory

The removed tissue is collected for examination under a microscope. I use the tissue result and the colonoscopy findings to advise you about follow-up. Some complex polyps may require a separate procedure; occasionally surgery is needed.