Colon Polyps

Colon polyps are diagnosed and treated by the GI Division of Premier Medical Group.

What are colon polyps?

A colon polyp is a small clump of cells that form on the lining of the colon, also called the large intestine. Colon polyps can be flat or raised and rarely cause symptoms. A person can have more than one colon polyp. Most polyps are harmless, but some can become cancerous over time. A colon polyp is generally found during a colonoscopy screening, and if found in the early stages frequently can be removed completely and safely. Anyone can develop polyps, but people 50 or older, overweight, smokers, or those with family history of cancers are at a higher risk.

1 in 15 Americans will develop colon cancer by the time they are 65 and since colon cancer is the 2nd most common cause of cancer death, and most colon cancers develop from a polyp, it is imperative to be screened and follow through with colon polyp removal.

What are the causes of colon polyps?

Back to top

Polyps are caused by abnormal cell growth. Healthy cells grow and divide, a process that’s controlled by two groups of genes, and when there are mutations in any of these genes, it causes cells to continue dividing even when new cells are not needed. The unregulated growth in the colon can cause polyps to form.

Over time, these growths can become cancerous, so colon polyp removal is generally recommended. Polyps can develop anywhere in the large intestine, and they can be small, large, flat or mushroom shaped. Usually, the larger the polyp the greater the likelihood of cancer is.

Anyone can get colon polyps, but certain people are more likely to get them than others. People with risk factors for colon polyps:

  • 50 years and older
  • Have a family history of polyps
  • Have a family history of colon cancer
  • Had uterine or ovarian cancer before age 50
  • Eat fatty foods
  • Smoke
  • Drink alcohol
  • Are overweight

What are the symptoms of colon polyps?

Back to top

Colon polyps generally do not cause any symptoms. Most people do not even know they have a polyp until their doctor finds it during a routine check-up, such as a colonoscopy or sigmoidoscopy.

If you have symptoms, they can include:

  • Blood in the stool (sometimes hidden)
  • Change in bowel habits
  • Rectal bleeding
  • Abdominal pain or obstruction
  • Anemia (low blood count)

These colon polyp symptoms are often a sign that there is significant polyp growth in your intestine. Do not wait to seek out medical attention, especially if you are due for a colonoscopy or other colon polyp screening.

How are colon polyps diagnosed?

Back to top

There are several tests that can be used to detect and diagnose colon polyps. Since polyps don’t generally present any symptoms, unless they are large and cause bleeding, the best way to diagnose them is a test that explores the inside surface of the colon. The most common methods are a colonoscopy or flexible sigmoidoscopy. Since nearly all colon cancers develop from polyps and since polyps grow very slowly, colon polyp screening plays a very important role in identifying polyps before they become cancerous.

Colon polyp screening tests include the following:

  • Fecal blood tests: Your doctor will give you a kit to take home for this test. Following the instructions on the kit is very important because certain foods can alter the results. When you return the kit to your doctor or lab, the stool sample will be checked for blood. This can be indicative of polyps or colon cancer.
  • Colonoscopy: This is the most commonly used and most sensitive screening method for both colon polyps and colon cancer. A colonoscopy procedure is performed with a long, slender, flexible tube attached to a video camera and monitor, and allows the doctor to view the entire colon and rectum. If your doctor finds polyps during the exam, he or she will want to remove them immediately and send tissue samples to a lab for analysis (biopsy). Preparation for a colonoscopy exam involves cleansing your bowel with laxatives and restricting your diet the day prior to the exam. Often, split-dose colonoscopy prep is recommended in which you take half the laxative dose the night before and the other half in the morning before the procedure. Your doctor may also give you a mild sedative to relax you before and during the exam
  • Flexible sigmoidoscopy: The difference between a colonoscopy and sigmoidoscopy is the length of the instrument. A sigmoidoscopy views the last third of your colon, or about two feet (61 centimeters), while the colonoscopy tube screens the entire colon. Presence of polyps in this area could be indicative of problem elsewhere. If your doctor finds a polyp during a sigmoid exam, he or she will want to perform a colonoscopy to check the rest of the colon.
  • Barium enema: This diagnostic test allows your doctor to evaluate your entire large intestine with an X-ray and contrast solution containing barium. The solution is then placed into your bowel using an enema bag, coating the bowel lining and producing an outline of your rectum.  Polyps can be missed using this method, and it does not allow for removal if a polyp is found. The barium enema is designed to screen for cancer, not polyps, and it is not very sensitive or specific.
  • Computerized tomographic colonography (CTC) (Virtual colonoscopy): This test uses computer imaging to view every part of your colon and rectum, without actually going inside your body. Preparation involves clearing the large intestine of any stool. This new technology may make colon screening more comfortable, safer, and less invasive. It’s quick and does not require sedation. Accuracy of the virtual exam is not proven at this time, and this method does not allow your doctor to remove polyps or take tissue samples. If polyps are found, you will still need a colonoscopy. At present it is still considered experimental and not covered by most insurances.


What are the types of colon polyps?

Back to top

There are many different types of colon polyps, as well as multiple approaches for classifying the different types. In terms of the nature of the growth, there are both adenomatous polyps caused by tumors and inflammatory polyps. Inflammatory polyps are also known as pseudo-polyps and while benign themselves are often the sign of some other underlying condition such as inflammatory bowel disease, Crohn’s disease, or ulcerative colitis.


In terms of general shape, there are sessile (flat) polyps and pedunculated (raised) polyps. Flat polyps are harder to detect. In terms of growth pattern, there are tubular (tube-like), villous (finger-like), and tubulovillous (tubes and fingers) polyps. Colon polyps can also be serrated. One specific type of small, serrated polyp is known as hyperplastic. These polyps are nearly always benign but are still removed and tested to be certain. Complex polyps, or “defiant” polyps, are either too big (>2cm), in a high-risk location, and/or too flat for removal during a standard colonoscopy.

How are colon polyps treated?

Back to top

Colon polyps are generally removed during a colonoscopy or sigmoidoscopy. The tissue is sent to a lab to be tested for cancer. Patients who have polyps should be screened more regularly than people who do not. Some polyps are more likely to be cancerous than others, which makes it so important for your doctor to remove all polyps discovered during the screening. Complex polyp removal requires more advanced surgical procedures.

How are colon polyps removed?

The most common method for colon polyp removal is referred to as snaring. The doctor uses a wire loop that cuts the stalk of the polyp and cauterizes it at the same time to prevent bleeding.

If the polyp is too large to be “snared”, your doctor may refer you to a surgeon for surgery. The  section that contains the large polyps is removed, alleviating any chance of a new polyp recurring in that area. Of course, new polyps can grow in other areas of the colon.

Endoscopic mucosal resection
A new technique called endoscopic mucosal resection (EMR) is performed in larger specialized facilities to remove larger polyps. For this newer technique a liquid, such as saline, is injected under the polyp to elevate and isolate the polyp from surrounding tissue. This makes large colon polyp removal easier. With this procedure, you can avoid surgery, but because it a relatively new and uncommon procedure it’s not yet clear what the complications may be.

Colon and rectum removal
In cases of rare, inherited syndromes, such as familial adenomatous polyposis (FAP), your surgeon may perform an operation to remove your entire colon and rectum (total proctocolectomy). He then attaches an ileal pouch, which allows you to expel waste normally, although you may have watery and more frequent bowel movements.

Helpful tips to prevent polyps:

  • Eat more fruits and vegetables
  • Avoid smoking
  • Avoid alcohol
  • Eat less fatty and fried foods
  • Exercise regularly
  • Maintain healthy weight
  • Eat foods with more calcium such as cheese, yogurt, and broccoli, and drink milk
  • Take a low dose of aspirin each day