Colonic polyps, also known as colorectal polyps, are benign (noncancerous) growths that appear on the surface of your colon. The colon, or large intestine, is a long hollow tube at the bottom of your digestive tract. It’s where your body makes and stores stool. Polyps in the colon can vary in size and number. Most polyps are harmless, but they can slowly progress into cancer over time. Colon cancer is a serious condition that can be life-threatening in its later stages.
Colonic polyps can occur in anyone, but people over age 50 are most at risk. You also have a higher risk of getting polyps in the colon if you’re overweight, a smoker, or have a family history of colon cancer.
Since colonic polyps usually don't cause symptoms, it's important to have regular screening tests that can detect any existing polyps. When colonic polyps are found in the early stages, they can often be removed safely and completely. Removing potentially cancerous polyps may reduce your risk of developing colon cancer.
The symptoms of colonic polyps can vary from person to person. Some people don’t experience any symptoms, so polyps often go undetected until they’re discovered by a doctor. Your doctor may find colonic polyps while performing a physical exam or a diagnostic test for another condition. However, if you do experience symptoms, they may include:
- blood in the stool
- diarrhea or constipation that lasts longer than one week
- anal bleeding
If you notice blood on the toilet paper or your underwear after a bowel movement, this can indicate anal bleeding. Blood in your stool may appear black or have red streaks.
Doctors don’t know the exact cause of colonic polyps, but polyps usually result from abnormal tissue growth. The body periodically develops new healthy cells to replace old cells that are damaged or no longer needed. The growth and division of new cells is usually regulated. In some cases, however, new cells grow and divide before they’re needed. This excess growth causes polyps to form. The polyps can develop in any area of the colon.
Although the specific cause of colonic polyps isn’t known, there are certain factors that can increase your risk of developing polyps. These include:
- being over age 50
- having a family history of polyps or colon cancer
- having had polyps in the past
- having had ovarian or uterine cancer before age 50
- having an inflammatory condition that affects the colon, such as Crohn’s disease or ulcerative colitis
- having uncontrolled type 2 diabetes
- having a hereditary disorder, such as Lynch syndrome or Gardner’s syndrome
Unhealthy behaviors that may contribute to the growth of colonic polyps include:
- being overweight
- frequently drinking alcohol
- exercising infrequently
- eating a high-fat diet
You may be able to lower your risk for colonic polyps if you make lifestyle changes to address these behaviors. Regularly taking a low dose of aspirin and adding more calcium to your diet may also help prevent polyps. Your doctor may have other suggestions for reducing your risk.
Your doctor may perform a series of tests to identify colonic polyps. These tests include:
- Colonoscopy: During this procedure, a camera attached to a thin, flexible tube is threaded through the anus. This allows your doctor to view the rectum and colon. If a polyp is found, your doctor can remove it immediately or take tissue samples for analysis.
- Sigmoidoscopy: This screening method is similar to a colonoscopy, but it can only be used to see the rectum and lower colon. It can’t be used to take a biopsy, or a sample of tissue. If your doctor detects a polyp, you'll need to schedule a colonoscopy to have it removed.
- Barium enema: For this test, your doctor injects liquid barium into your rectum and then uses a special X-ray to take images of your colon. Barium makes your colon appear white in the pictures. Since polyps are dark, they’re easy to identify.
- CT colonography: This procedure uses a CT scan to construct images of the colon and rectum. After the scan, a computer combines the images of the colon and rectum to produce both 2- and 3-D views of the area. A CT colonography is sometimes called a virtual colonoscopy. It can show swollen tissues, ulcers, and polyps.
- Stool test: Your doctor will give you a test kit and instructions for providing a stool sample. You'll return the sample to your doctor's office for analysis, especially to test for microscopic bleeding.
The best way to treat colonic polyps is to remove them. Your doctor will likely remove your polyps during a colonoscopy. The polyps are then tested for cancer, unless your doctor has already determined that they’re benign, or noncancerous. Doctors can usually get rid of polyps without performing surgery.
However, you may need laparoscopic surgery to remove the polyps if they’re large and can’t be removed during a colonoscopy. Laparoscopic surgery is a minimally invasive procedure that uses an instrument called a laparoscope. A laparoscope is a long, thin tube with a high-intensity light and a high-resolution camera at the front. The instrument is inserted through an incision in the abdomen. Once your doctor has a visual of your colon, they’ll remove the polyps using a special tool.
A pathologist, or someone who specializes in tissue analysis, will check the polyps for cancer. The results will then be sent to your doctor.
Colonic polyps are usually noncancerous and considered harmless. Removing polyps may reduce or eliminate any related symptoms you were experiencing. It can also help prevent colon cancer in the future.
Since you have a higher risk of developing more polyps in the future, your doctor will recommend additional screenings in three to five years.
Maintaining a healthy diet can help prevent the development of colonic polyps. This includes eating more fruits, vegetables, whole grains, and lean meat. You may also be able to prevent polyps by increasing your intake of vitamin D and calcium. Food that are rich in vitamin D and calcium include:
You can further lower your risk for colonic polyps by reducing your intake of high-fat foods, red meat, and processed foods. Quitting smoking and exercising regularly are also important steps to take to prevent the development of colonic polyps.