Colon polyps are clumps of cells that form on the lining of the colon. They range in size from smaller than a pea to the size of a golf ball. Although most colon polyps are not cancerous, some can become cancerous over time. It usually takes many years for a polyp to turn cancerous.
Anyone can develop polyps in their colon, but those who are age 50 or older, are overweight, smoke, eat a high-fat, low-fiber diet, or have a personal or family history of colon polyps are at a higher risk.
Most small colon polyps don’t cause symptoms. They are usually found during screening tests for colon cancer. If polyps become larger, they can cause symptoms such as rectal bleeding, a change in bowel habits, blood in your stool, diarrhea, constipation or abdominal pain.
Remember that colon polyps found in their early stages can usually be removed completely and safely.
Why do polyps form?
Although most polyps aren’t cancerous, they are the result of abnormal cell growth like cancer. Polyps can develop anywhere in the large intestine. There are three main types of colon polyps:
Adenomatous – once this type of polyp grows beyond the size of a pencil eraser, about ¼ inch, there is an increasing chance that they will become cancerous. This is why doctors normally take a tissue sample, known as a biopsy, from polyps during a sigmoidoscopy exam. If a colonoscopy is being performed, the polyp can be biopsed or removed during the procedure.
Hyperplastic – this type of polyp occurs most often in the descending (left) colon and rectum. They are usually less than 5mm in size and rarely malignant (cancerous).
Inflammatory – these polyps may follow a bout of ulcerative colitis or Crohn’s disease. They are usually not dangerous, but having ulcerative colitis or Crohn’s disease can increase your risk of colon cancer.
Treating colon polyps
During a bowel examine, your doctor will usually remove all polyps that are discovered so they can be examined by a pathologist. By examining a polyp under a microscope, a pathologist can determine whether it is cancerous or not.
Most polyps can be removed during a colonoscopy or sigmoidoscopy by snaring them with a wire loop that simultaneously cuts the stalk of the polyp and cauterizes it to prevent bleeding. Some small polyps are cauterized or burned using electrical current.
Polyps are surgically removed if they are too large to snare or can’t be reached in a safe manner. This is usually done through laparoscopic surgery.
After you have a polyp removed, follow-up care is very important, since you will have a greater chance of developing new polyps. Your doctor will inform you of follow-up tests and warning signs to watch for.