A polyp is a growth in the lining of the bowel. A polyp can be sessile (no stalk) or on a stalk or stem.
There are three main kinds of polyps:
- Serrated Polyps – these have an accelerated path to malignancy.
- Adenomatous Polyps – these can develop into cancer.
- Hyperplastic Polyps – thought to have a low risk of progressing to a cancer.
If Polyps are left then they have the risk of turning into cancer.
How Do Polyps Turn into Cancer?
The progression of a polyp to cancer is now well understood. A polyp forms and over time, grows larger as it progressively undergoes genetic changes. Eventually over a five to ten year period it may transform into a cancer as it accumulates genetic defects. It is therefore essential to check for polyps and remove them. Early detection can eradicate the chance of cancer.
What are the symptoms of Polyps?
Colonic polyps often cause no symptoms and are only found during investigation. Occasionally polyps result in bleeding, pain, or the passing of mucous with bowel motions.
How do I Check if I have Polyps?
During a colonoscopy, polyps can be seen through the camera. If a polyp is found it will often be removed there and then – this removes the chance that this polyp will develop into cancer.
If you have had a big polyp, a high risk polyp or more than three polyps, then you should have a colonoscopy at least every three years. If you have someone in your family who has had polyps or bowel cancer then regular colonoscopies are recommended.
By removing polyps we prevent bowel cancer!
How are Polyps treated?
During the colonoscopy an instrument can be inserted through the colonoscope to obtain a biopsy or tissue sample for laboratory analysis.
This instrument can also be inserted to cauterise the polyp and the tiny vessels supplying it with blood and as a result the polyp can then be removed.
There is no sensation inside the colon so when the tissue is removed you will not feel it. Most polyps can be removed safely this way but very large polyps may need to be taken out surgically.
Do Colonic Polyps run in the family?
Yes. If you have family members who have polyps or who have had bowel cancer then your chance of developing Polyps and Cancer is increased.
You should consider screening colonoscopies. These are routine scopes, without symptoms, to check for the development or change of polyps.
When should I start Screening Colonoscopies?
As a general rule it is a good idea to begin screening at 45-50 years. The screen should then be repeated every 3-5 years.
Because New Zealand has such a high prevalence of bowel cancer (about 2000 new cases each year), and because is so easily prevented, New Zealand has just begun a nationwide Bowel Cancer Screening Programme. While a great start, this publicly funded screening uses a stool specimen to identify risk, not the gold standard of a colonoscopy. It is therefore recommend that screening colonoscopies be undertaken.