Understanding Polyps and Their Treatment

What Is a Colon Polyp?

peb06_3Polyps are benign growths (noncancerous tumors or neoplasms) involving the lining of the bowel. They can occur in several locations in the gastrointestinal tract but are most common in the colon. They vary in size from less than a quarter of an inch to several inches in diameter. They look like bumps growing from the inside lining of the bowel protruding out. They sometimes grow on a “stalk” and look like mushrooms. Some polyps can be flat. People can have several polyps scattered in different parts of the colon. Some polyps can contain cancer, although the vast majority of polyps do not. Larger polyps are more likely to become cancerous than smaller ones.

How Common Are Colon Polyps? What Causes Them?

While uncommon in 20 year olds, more than 40% of persons over 50 have precancerous polyps in the colon. Smoking, obesity, diabetes, and inadequate exercise are risk factors for polyps, but many people with none of these risk factors have precancerous polyps in the colon. There are genetic risk factors for developing polyps as well.

What Are Known Risks for Developing Polyps?

The biggest risk factor for developing polyps is being older than 50. A family history of colon polyps or colon cancer increases the risk of polyps. Also, people with a personal history of polyps or colon cancer are at higher risk of developing new polyps in the future than a person who has never had a polyp. In addition, there are some rare “syndromes” that run in families which increase the risk of forming polyps and cancers, even at younger ages.

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There are two common types: hyperplastic polyp and adenoma. The hyperplastic polyp is not at risk for cancer. The adenoma, however, is thought to be the precursor (origin) for almost all colon cancers, although most adenomas never become cancers. Histology examination of tissue under a microscope) is the best way to differentiate between hyperplastic and adenomatous polyps.

Although it’s impossible to tell which adenomatous polyps will become cancers, larger polyps are more likely to become cancers and some of the largest ones (those larger than 1 inch) can already contain small areas of cancer. Because your doctor cannot be certain of the tissue type by the polyp’s appearance, doctors generally recommend removing all polyps found during a colonoscopy.

How Are Polyps Found?

Most polyps cause no symptoms. Larger ones can cause blood in the stools, but even they are usually asymptomatic. Therefore, the best way to detect polyps is by screening individuals with no symptoms. Several other screening techniques are available: testing stool specimens for traces of blood, performing sigmoidoscopy to look into the lower third of the colon, or using a radiology test such as a barium enema or CT colonography. If one of these tests finds or suspects polyps, your doctor will generally recommend colonoscopy to remove them. Because colonoscopy is the most accurate way to detect polyps, many experts now recommend colonoscopy as a screening method so that any polyps found or suspected can be removed during the same procedure.

How Are Polyps Removed?

Almost all precancerous polyps found during colonoscopy can be completely removed during the procedure. Various removal techniques are available; most involve removing them with a wire loop or biopsy forceps, sometimes using electric current. This is called polyp resection or polypectomy. Because the bowel’s lining isn’t sensitive to cutting or burning, polyp resection doesn’t cause discomfort.

What Are the Risks of Polyp Removal?

Polyp removal (or polypectomy) during colonoscopy is a routine outpatient procedure. Possible complications, which are uncommon, include bleeding from the polypectomy site and perforation (a hole or tear)  of the colon. Bleeding from the polypectomy site can be immediate or delayed for several days; persistent bleeding can almost always be stopped by treatment during a repeat colonoscopy. Perforations rarely occur and can sometimes be closed with clips during the colonoscopy, but other times require surgery to repair.

How Often Do I Need a Colonoscopy if I Have Polyps Removed?

The timing of your next colonoscopy depends on several factors, including the type, number and size of polyps removed. The quality of cleansing affects your doctor’s ability to see the inside surface of the colon where polyps form. If your colon is inadequately cleansed,  your doctor may recommend repeating a colonoscopy sooner. Your doctor will decide when your next colonoscopy is necessary.

IMPORTANT REMINDER: The preceding information is intended only to provide general information and not as a definitive basis for diagnosis or treatment in any particular case. It is very important that you consult your doctor about your specific condition.

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