What is a bowel polyp?
A polyp is a small growth of tissue that forms on the inner lining of the bowel wall. They're very common — found in roughly 30–40% of Australians over 50, and more so with age. The vast majority are completely harmless and will never cause any trouble. However, certain types can slowly develop into bowel cancer over many years, which is exactly why finding and removing them matters so much.
Here's the reassuring part: bowel cancer almost always starts from a polyp, and the process is slow — typically 10 to 15 years from an early pre-cancerous polyp (called an adenoma) to invasive cancer. That window of time is exactly what colonoscopy is designed to catch. Removing a polyp now breaks the chain before cancer ever develops.
Types of polyps: not all are the same
The type of polyp found determines how significant it is and what the recommended follow-up (surveillance) looks like. This is something the pathology lab determines after examining the removed tissue — so you won't know the exact type until the results come back.
Lower-risk polyps
- Hyperplastic polyps — very common, almost always completely harmless, typically small and found in the rectum or lower colon. Don't require intensive follow-up.
- Small tubular adenomas (under 10 mm, 1–2 found) — a mildly increased risk; surveillance is recommended, but at a fairly long interval of 5 years.
- Small sessile serrated lesions (under 10 mm, no dysplasia) — an increasingly recognised type; surveillance is typically 5 years.
Higher-risk polyps
- Advanced adenomas — any adenoma 10 mm or larger, or one that contains high-grade dysplasia (abnormal cells), or has a villous pattern. Carries a significantly higher cancer risk and needs closer follow-up.
- Three or more adenomas — having multiple adenomas increases risk, even if each individual one is small.
- Larger or dysplastic sessile serrated lesions — these are associated with a type of bowel cancer (serrated pathway cancer) that can sometimes develop more quickly.
The pathology result is what determines your polyp type — this is why every polyp removed is always sent to a laboratory for examination under a microscope. Once the result is back, Mr Nguyen can recommend your specific surveillance interval.
How are polyps removed? (Polypectomy)
If a polyp is found during your colonoscopy, it can usually be removed on the spot — this is called a polypectomy. You won't feel it happening; the procedure is done while you're sedated. The technique depends on the size, shape, and location of the polyp.
Cold snare polypectomy
A small wire loop (called a snare) is passed through the colonoscope and looped around the base of the polyp. The wire is tightened to cut the polyp off mechanically — no electrical current is involved. Cold snare is the preferred technique for most polyps up to about 10 mm in diameter. It's very safe with a very low risk of bleeding or other complications.
Hot snare polypectomy
For larger polyps, the snare is combined with electrocautery — a gentle electrical current is passed through the wire to simultaneously cut and heat-seal the base of the polyp. This helps prevent bleeding from the larger blood vessels at the polyp base. Hot snare carries a slightly higher risk of delayed bleeding (sometimes hours to days after the procedure) compared with cold snare.
Endoscopic mucosal resection (EMR)
For large, flat, or difficult-to-reach polyps, a technique called endoscopic mucosal resection (EMR) may be used. A liquid solution is injected beneath the polyp to gently lift it away from the bowel wall, and it's then removed in sections. Because EMR removes the polyp in pieces, you may be asked to come back for a check colonoscopy a few months later to confirm the site has healed completely.
Biopsy only
Occasionally, a polyp is too large or in a position where immediate removal wouldn't be safe. In this case, small tissue samples (biopsies) are taken to determine the polyp type, and Mr Nguyen will discuss your options — which might include a planned endoscopic removal session, laparoscopic surgery, or careful monitoring depending on what the pathology shows.
All removed polyp tissue is sent to a pathology laboratory. Results usually take one to two weeks. Once the histology (microscopic analysis) is back, Mr Nguyen's rooms will contact you to talk through what was found and what your recommended follow-up interval is.
Surveillance intervals after polypectomy
Once polyps have been removed, Mr Nguyen will recommend a timeframe for your next colonoscopy. This follow-up is called surveillance, and the interval depends on the number, size, and type of polyps found — following national NHMRC (National Health and Medical Research Council) guidelines.
Typical surveillance intervals (NHMRC-aligned)
- No polyps found: Return to standard screening — a repeat colonoscopy or FOBT (bowel cancer screening test) in 5–10 years depending on your age and risk factors.
- 1–2 small tubular adenomas (under 10 mm): Lower risk — surveillance colonoscopy in 5 years.
- 3–4 small adenomas, or any adenoma 10–19 mm: Intermediate risk — surveillance colonoscopy in 3 years.
- 5 or more adenomas, or any adenoma 20 mm or larger, or high-grade dysplasia: Higher risk — surveillance colonoscopy in 1 year.
- Small sessile serrated lesions (under 10 mm, no dysplasia): Surveillance in 5 years.
- Larger or dysplastic sessile serrated lesions: Surveillance in 1–3 years depending on specific features.
These are guidelines, not fixed rules. Your personal picture — including your family history, any previous polyp history, the quality of your bowel preparation, and whether all polyps were completely removed — may lead to a different recommendation. Mr Nguyen will explain the reasoning for your specific follow-up plan so you understand exactly what's being recommended and why.
After polypectomy: what to expect and watch for
Most polypectomies go smoothly and you'll go home the same day. There are a few important things to follow in the days afterwards to let the healing site settle properly:
- Diet: Stick to light, easy-to-digest food on the day of the procedure. Avoid high-fibre, spicy, or fatty foods for the first 24–48 hours.
- Activity: Avoid strenuous exercise and heavy lifting for 48–72 hours. You can build back up to normal activity gradually over the following days.
- Medications to avoid: Do not take anti-inflammatory painkillers — ibuprofen (Nurofen), naproxen, or diclofenac — for seven days after a polypectomy. These medications affect how your blood clots and can increase the risk of bleeding. If you need pain relief, paracetamol is safe to use.
- Alcohol: Avoid alcohol for at least 24 hours after sedation, and for longer (up to 7 days) if advised — especially after a larger polypectomy.
- Blood-thinning medications: Do not restart anticoagulants (like warfarin, rivaroxaban, or apixaban) or antiplatelet medications (like clopidogrel) until Mr Nguyen specifically confirms it's safe to do so.
Go to your nearest emergency department urgently if you develop: significant fresh rectal bleeding (soaking through a pad, passing clots, or blood filling the toilet bowl), severe abdominal pain, a fever above 38°C, or vomiting that won't settle. These are uncommon but can occasionally be signs of a post-polypectomy complication that needs prompt attention.
What if polyps cannot be fully removed?
Occasionally a polyp is too large, or in a position where it's not safe or feasible to remove it completely in one session. If this happens, there are a few options:
- Staged endoscopic removal: The polyp is removed in stages over two or more separate colonoscopy sessions. A short-interval check colonoscopy is then done to confirm everything has been cleared.
- Laparoscopic (keyhole) surgery: For very large polyps, or if there's any concern about cancer, surgical removal of the affected segment of bowel may be the safest option. This can often be done laparoscopically — through small keyhole incisions rather than a large open cut. Mr Nguyen is a specialist colorectal surgeon who performs this operation.
- Endoscopic submucosal dissection (ESD): A more advanced endoscopic technique that allows the polyp to be removed in one piece even when it's large. This is performed at specialist centres and may be an option for certain patients.
If cancer is found
In a small number of colonoscopies, a suspicious area is found that may represent early bowel cancer rather than a pre-cancerous polyp. If this happens, biopsies will be taken, and Mr Nguyen will contact you once the pathology results are back to discuss what they mean. Please know that early-stage bowel cancer detected at colonoscopy carries an excellent prognosis — the earlier it's found, the better the outcome. Mr Nguyen will explain the next steps, which usually include a CT scan to gather more information and a discussion of treatment options. For early cancers, this may involve further endoscopic removal or laparoscopic surgery with the intent to cure.
Frequently asked questions
Yes — before you leave, Mr Nguyen will come and tell you how many polyps were found and what was done with them. Photographs taken during the procedure will be included in your procedure report. However, the exact type of polyp (the histology) can only be determined once the pathology result comes back — which usually takes one to two weeks.
No. Polypectomy is done while you're sedated, so you won't feel anything during the procedure. The inner lining of the bowel doesn't have the same pain receptors as skin, so polypectomy itself is painless — though sedation is still given for your comfort and safety throughout.
No. The vast majority of polyps are benign (non-cancerous) and haven't progressed to anything harmful. Finding and removing a polyp before it becomes cancerous is exactly what colonoscopy is designed to do. Even the higher-risk types — advanced adenomas — are not cancers. They're pre-cancerous growths, and removing them is how you prevent cancer from ever developing.
Avoid anti-inflammatory medications — ibuprofen (Nurofen), naproxen, diclofenac, and aspirin at anti-inflammatory doses — for seven days after polypectomy. Paracetamol is safe to use. If you're taking prescribed aspirin for heart disease or a stroke history, don't stop it without speaking to Mr Nguyen or your GP first, as this needs individual advice.
Three adenomas places you in an intermediate surveillance category, which means your next colonoscopy will likely be recommended in about three years. This is not a frightening finding — it just means we keep a closer eye on things than for someone with no polyps. Attending your scheduled surveillance colonoscopies is the single most effective thing you can do to protect yourself. Regular surveillance and polyp removal substantially reduces your lifetime cancer risk.
Not necessarily. Many people with lower-risk findings (1–2 small adenomas) need only one or two surveillance colonoscopies before returning to standard screening intervals. Your plan will be reviewed after each examination based on what's found — so if things look reassuring each time, the intervals can get longer, not shorter.
Learn more about this procedure — including what to expect, benefits, risks, and recovery.
Procedure details →Have questions about your polyp results?
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