The information on this page was reviewed and approved by
Maurie Markman, MD, President, Medicine & Science at CTCA.

This page was updated on September 21, 2021.

Colon polyps

A colon polyp is a small growth of tissue inside the colon, or large intestine. Although most colon polyps are harmless, some could turn into colorectal cancer or already be cancerous.

Screening tests, including a colonoscopy, can help detect colon polyps. 

What causes colon polyps?

Although researchers don’t know the exact cause of colon polyps, certain factors could increase a patient’s risk of developing them. These risk factors include:

  • Being older than age 50
  • Having a family member who has had colon polyps before
  • Having a family member who has had colon cancer before
  • Having had a previous diagnosis of colon polyps

Types of colon polyps

Colon polyps can come in various shapes and sizes. They may range from several millimeters to a few centimeters in size, and may also be raised or flat. 

  • If colon polyps are raised, they might look like small bumps. These are called sessile polyps. 
  • In other cases, raised colon polyps may look like a small cauliflower or mushroom and grow on short stalks. These polyps are called pedunculated polyps.

Symptoms of colon polyps

Colon polyps often develop silently, which means they usually don’t cause symptoms. In some cases, though, you may notice signs such as:

  • Blood in stool
  • Constipation or diarrhea that persists longer than a week
  • Feeling tired due to anemia and lack of iron, which can happen if there is bleeding from the colon
  • Rectal bleeding, which could show up on toilet paper or in underwear

How colon polyps are diagnosed

Doctors can diagnose colon polyps by using a screening test for colorectal cancer. Expert groups recommend everyone with an average risk of developing colorectal cancer undergo screening regularly, beginning between the ages of 45 and 50 and continuing through age 75. Between ages 75 and 85, your doctor can help you decide whether it would benefit you to continue screening. If you’re above the age of 85, you no longer need to receive colorectal cancer screening.

If you have a high risk of developing colorectal cancer, you may need to begin screening before you turn 45. The following factors raise a person’s risk of developing colorectal cancer:

  • Certain polyps or colorectal cancer run in your family
  • Hereditary colorectal cancer syndromes run in your family, including Lynch syndrome, and familial adenomatous polyposis
  • You’ve had certain polyps or colorectal cancer before
  • You’ve received radiation therapy to the abdominal area or pelvic area for the treatment of an earlier cancer
  • You have Crohn’s disease or ulcerative colitis (UC), which are inflammatory bowel diseases

Types of colorectal cancer screening tests:

  • Colonoscopy, which involves using a tool called a colonoscope to see the colon and rectum
  • Sigmoidoscopy, which involves using a tool called a sigmoidoscope to assess the rectum and sigmoid colon, or the portion of the colon that is shaped like an “S” and attaches to the rectum
  • Stool tests, which test for blood in stool (which can happen if you have polyps or colorectal cancer) or cell changes
  • Virtual colonoscopy, which is a noninvasive method involving the use of X-ray tools to provide images of the colon and rectum

How are colon polyps treated?

The doctor will treat colon polyps by removing them, either through colonoscopy or flexible sigmoidoscopy. Both colonoscopes and sigmoidoscopes have a light and a lens (inserted into the colon) to view the lining of your colon and rectum, as well as a tool to remove colon polyps.

If your doctor removes colon polyps, be sure to let your doctor know if you experience any of the following issues afterward:

  • Dizziness
  • Fever
  • Persistent bloody stools
  • Persistent rectal bleeding
  • Severe abdominal pain
  • Weakness

How to lower your risk of colon polyps

Eating a healthy diet may reduce your risk of developing colon polyps. Specifically, research suggests that eating a diet rich in fruits, vegetables and fiber-containing foods such as bran cereal and beans may help prevent colon polyps.

Additionally, it’s important to limit certain foods in order to lower your risk of developing colon polyps. Be sure to reduce your intake of high-fat foods such as:

  • Fried foods
  • Red meats, including beef and pork
  • Processed meats, such as lunch meats, sausage, bacon and hot dogs

If you’re overweight, losing weight can help lower the risk of developing colon polyps. If you’re already at a healthy weight, try to maintain your weight and avoid weight gain.