A colon polyp is a growth that occurs on the wall of the large intestine, or colon. A polyp that is flat in shape is called sessile, and one that has a long stalk is called pedunculated. Polyps are common in people over the age of 40 and often grow slowly. Polyps can develop into colon cancers, which is why they are typically removed during a colonoscopy.
Symptoms of Colon Polyps
In most cases, polyps do not cause any symptoms. Because they typically don't cause symptoms, polyps can go undetected until they are found during a colonoscopy or other test on the colon. When polyps do cause symptoms, they can include:
- Blood in the stool (black or red).
- Bleeding from the rectum.
- Constipation or diarrhea that doesn't go away.
Those at Risk for Colon Polyps
Certain people are more at risk for developing polyps in their colon than others, because of age or family history. Some of these risk factors include:
- Age over 50 years.
- A family history or personal history of polyps.
- A family history of colon cancer.
- A personal history of cancer in the uterus or the ovaries.
- A high-fat diet.
- A history of cigarette smoking.
- A history of drinking alcohol
- A sedentary lifestyle.
There is no one specific way to prevent developing colon polyps, but living a healthier lifestyle by eating properly, exercising, and not smoking or drinking may help. Calcium, folic acid supplements, and a daily low dose of aspirin may also protect against the development of polyps.
Some rare genetic conditions can cause polyps to grow in younger people, even teenagers. People who have these disorders, hereditary non-polyposis colon cancer (HNPCC [also known as Lynch syndrome]), Peutz-Jeghers syndrome, and familial adenomatous polyposis (FAP), are at increased risk of developing colon cancer.
Types Of Polyps
There are four main types of colon polyps: adenomatous (tubular adenoma), hyperplastic, inflammatory, and villous adenoma (tubulovillous adenoma).
Adenomatous or Tubular Adenoma. This type of polyp has a risk of turning cancerous, and is the most common. When this type of polyp is found, it will be tested for cancer. Anyone who has these polyps will need periodic screening to check for any more polyps and to have them removed.
Hyperplastic. These polyps are common, small, and are at a low risk of turning cancerous. Any hyperplastic polyps found in the colon would be removed and tested to ensure they are not cancerous.
Villous Adenoma or Tubulovillous Adenoma. This type of polyp carries a high risk of turning cancerous. They are commonly sessile, which makes them more difficult to remove.
Inflammatory Polyps. Inflammatory polyps most often occur in people who have inflammatory bowel disease (IBD). These types of polyps are also known as pseudopolyps because they are different from the other three forms, and do not turn cancerous. They occur as a result of the chronic inflammation that takes place in the colon of people with Crohn's disease and ulcerative colitis.
How Polyps Cause Colon Cancer
A polyp is a precancerous growth, which means that if it is left in place in the colon, it may turn cancerous. If it is removed, such as during a colonoscopy, it does not have the opportunity to turn cancerous. After a polyp is removed, it will be tested for cancer by a pathologist. Sessile polyps are more likely to turn cancerous than pedunculated polyps.
Colon Cancer Screening
People older than 50 should get screened for colon cancer -- except for patients in certain risk groups who need screening earlier and more frequently. Those who are at high risk for colon cancer because of a personal or family history of cancer are at higher risk and should be tested more frequently and at a younger age than those that don't have any risk factors. People who have inflammatory bowel disease (IBD), and especially those who have had ulcerative colitis for 10 years or more, are also at a higher risk for colon cancer.
Some tests that might be used to look for polyps include:
Polyps might be detected through the above tests, but can only be removed during a sigmoidoscopy or a colonoscopy.
If you are concerned about your risk of colon cancer, speak to your doctor about when and how often you should be screened.
American Society For Gastrointestinal Endoscopy. "Understanding Polyps and Their Treatment." ASGE.org 2011. 14 May 2014.
American Society Of Colon & Rectal Surgeons. "Polyps of the Colon and Rectum." FASCRS.org 2011. 14 May 2014.