Most polyps (90%) are called “adenomas” by the medical profession. They are very common, occurring in 15-20% of the population) and most of these are NOT cancerous.
What is a polyp?
A polyp is a protrusion or bump on the lining of the bowel (the mucosa) caused by an abnormal production of cells. It may be a tiny raised area; it may look like a small grape; or it may take the form of many tiny projections clustered together. Sometimes this last type is know as carpet or sessile polyp.
Polyps are important as, if they are not removed, they may eventually become a cancer in the colon (large bowel) or rectum (back passage), although this takes many years to develop.
Symptoms of polyps
Most people are unaware of having polyps as they produce no symptoms and they are often an incidental finding. Some polyps can, however, produce a small amount of bleeding or an excess production of mucus (slime) with bowel motions. Also, an alteration in bowel habit may occur and very large polyps may lead to a blockage in the bowel, but this is extremely unusual.
Polyps are usually found as a result of bowel investigations – such as a sigmoidoscopy, barium enema or CT colonography. If they are found, colonoscopy is required to view the whole of the large bowel.
Do polyps need to be removed?
Since there is no foolproof way of predicting whether or not a polyp will become a cancer, total removal of all polyps is advised.
Treatment for polyps
There are several methods for doing this but the most common is by:
- Snaring the polyp whilst you have a colonoscopy. Snaring is like cutting the polyp off with a cheese wire and is painless.
- Hot Biopsying removes the polyp by touching it with an electric probe. This is also painless.
- An operation to remove part of the bowel if the polyp has some cell changes or is large, but this is unusual.
After removal of the polyp/s, they are sent for pathology which will reveal whether the polyp has been completely removed, if there is any risk of it re-growing, and if there is any cancerous change in the polyp. If there is cancerous change in the polyp you may or may not require further treatment depending on the degree and extent of change. Your specialist will be able to advise you on this matter.
Follow-up after polyp removal varies but some people will require further colonoscopies because polyps can recur. Some bowel polyps run in families. This is uncommon, but if this condition is diagnosed, colonoscopy checks will be at regular intervals.