What are colon polyps?
A polyp in the colon can be defined as any extra tissue that protrudes into the inside (or lumen) of the large intestine (colon), but typically refers to excess of the lining (epithelium). They vary in size from microscopic to several inches in diameter.
What are the symptoms?
Typically there are no symptoms unless the polyps are large. However, patients may experience blood in the stool, constipation or diarrhea.
What are the risks of having polyps?
The greatest risk is that some types (primarily adenomas) may become cancerous. As adenomas grow in size, the chance of the growth eventually making a malignant transformation gets higher. It is estimated that it takes an average of approximately seven years for a small adenoma to become malignant. Another polyp type is hyperplastic polyp that has essentially no malignant potential, although recent evidence shows that a similar appearing polyp (once thought to be simply a large hyperplastic polyp), called a sessile serrated adenoma, carries a risk for the development of colonic cancer. Many other rare polyp types exist as well that are not associated with cancer risks.
How common are polyps?
For patients who are 50 years old, which is the recommended age for screening with a colonoscopy, the incidence is approximately 25 percent. The rate increases to 50 percent by age 70; so as we get older, the polyps are more frequently found.
What causes polyps?
There is a hereditary component to getting polyps. If family members have polyps, physicians strongly recommend that first-degree relatives (parents, siblings, children) have a colonoscopy at age 50 or earlier. Physicians believe that diet plays a role in the development of polyps. People on low fiber, high fat, high meat diets are more likely to have colon polyps. Also people inWestern countries develop polyps more frequently than those from countries in the East.
How are polyps diagnosed?
There are several tests that are commonly used to diagnose colon polyps. During a digital rectal exam, a physician feels for abnormalities in the lining of the rectum. A fecal occult blood test can detect tiny amounts of blood in the stool. During a double contract barium enema, or lower GI series, the physician puts a liquid containing barium into your rectum before taking X-rays of your large intestine. Bariumis impervious to X-rays, and therefore when coating the lining ofthe colon, polyps can be detected by a radiologist. A sigmoidoscope and colonscope use a thin flexible tube that has a light and a tiny video camera. The physician uses these to look at the last third or entirety of the large intestine, respectively. Because it is not possible to reliably distinguish the different types of polyps by looking at them with a colonscope alone, a biopsy sample (or complete removal) of polyps is usually taken by the gastrointestinal physician. The biopsy is then examined under a microscope by a surgical pathologist, preferably one with subspecialty training in gastrointestinal pathology, who can precisely determine what type of polyp is present and if any malignancy or other disease is present.
How are polyps treated?
Most polyps can be completely removed during a sigmoidoscopy or colonoscopy. Polyps can be removed painlessly during either procedure by inserting a surgical tool through the scope. This procedure is called polypectomy. Physicians frequently use an electrical wire loop that cuts through the tissue coagulating the vessels at the same time.When very large, surgical removal may be necessary.
How can I prevent polyps?
While there is no absolute way to prevent polyps, you may be able to lower your risk if you do the following:
- Eat more fruits and vegetables and less fatty food
- Don’t smoke
- Avoid alcohol
- Exercise every day
- Lose weight if you are overweight
What is the recommendation for a follow-up colonoscopy?
Whether or not you will need follow-up depends on the kind of polyp the surgical pathologist determinest hat you have. Your physician will discuss your individual situation and make a recommendation that is appropriate for you.
National Institute of Diabetes and Digestive and Kidney Diseases:
National Cancer Institute:
1.800.4.CANCER / www.cancer.gov
American College of Gastroenterology:
703-820-7400 / www.acg.gi.org/patients