Colon polyps risk factors: who is more likely to get them

What colon polyps are

Colon polyps are growths on the lining of your colon and rectum, and you can have more than one (NIDDK). The rectum is the last part of the large intestine. There are different types of polyps: most are benign (noncancerous), but some are precancerous and may turn into cancer over time (MedlinePlus).

Colorectal cancer most often begins as polyps, and removing polyps can help prevent colorectal cancer (NIDDK). This page is about polyps; for cancer itself, see colorectal cancer risk factors. There is no score or calculator for polyp risk on this page; the lists below are the factors NIDDK and MedlinePlus name.

How common colon polyps are

Colon polyps are common in American adults: NIDDK says anywhere between 15 and 40 percent of adults may have them. They are more common in men and older adults (NIDDK).

Who is more likely to get colon polyps

Anyone can develop colon polyps, but NIDDK says you may have a greater chance of developing them if you (NIDDK):

• are age 45 or older;
• have someone in your family who has had polyps or colorectal cancer;
• have inflammatory bowel disease such as ulcerative colitis or Crohn's disease;
• have obesity;
• smoke cigarettes.

MedlinePlus gives the same list and adds one more factor: having had polyps before (MedlinePlus). NIDDK also says that if you have had colon polyps, your doctor will ask you to get tested regularly in the future because you have a higher chance of developing more polyps (NIDDK). See also obesity risk factors.

What causes colon polyps

Experts are not sure what causes colon polyps. Research suggests that certain factors, such as age and family history, can raise your chances of developing them (NIDDK). MedlinePlus says the cause is unknown and that age, family history and lifestyle are believed to play a role (MedlinePlus).

Symptoms

Most people with colon polyps do not have symptoms, and you cannot tell you have polyps because you feel well (NIDDK). When polyps do cause symptoms, NIDDK and MedlinePlus list (NIDDK) (MedlinePlus):

• bleeding from your rectum: you might notice blood on your underwear or on toilet paper after a bowel movement;
• blood in your stool: blood can make stool look black or show up as red streaks;
• feeling tired because bleeding from polyps can lead to anemia and a lack of iron;
• changes in bowel habits, such as constipation or diarrhea that lasts more than a week (MedlinePlus).

Many other health problems can also cause these symptoms. However, if you have bleeding from your rectum or blood in your stool, NIDDK says to contact your doctor right away (NIDDK).

Screening and how polyps are found

Screening is testing for diseases when you have no symptoms, and finding and removing polyps can help prevent colorectal cancer (NIDDK). MedlinePlus says most adults should start colorectal cancer screening at age 45; if you are more likely to get polyps or colorectal cancer, your provider may suggest starting sooner or testing more often (MedlinePlus). Use our colon cancer screening age check to see which tests and intervals apply to you, and see screening tests by age.

Doctors can find colon polyps only by using certain tests or procedures. Your doctor may first take a medical and family history and do a physical exam to help decide which test is best for you (NIDDK). Tests include (NIDDK) (MedlinePlus):

• Colonoscopy: a long, flexible, narrow tube with a light and tiny camera is used to look inside your rectum and colon.
• Flexible sigmoidoscopy: a similar tube is used to look inside your rectum and lower colon.
• Virtual colonoscopy: x-rays and a computer create images of your rectum and colon from outside the body. Doctors cannot remove polyps during this test; if it finds a possible polyp, you will usually need a colonoscopy.
• Stool tests: these look for blood or other signs of colorectal cancer, and an abnormal result may require a follow-up colonoscopy.
• Lower GI series: x-rays and a chalky liquid called barium are used to view the large intestine (also called a barium enema).

Treatment

Doctors treat colon polyps by removing them. In most cases, they use special tools during a colonoscopy or flexible sigmoidoscopy, then send the polyp for testing to check for cancer. Doctors can remove almost all polyps without surgery (NIDDK). Rarely, surgery may be needed to remove a large polyp or part of the colon if it cannot be removed during one of these procedures (MedlinePlus).

NIDDK says to call your doctor right away if you have any of these symptoms after a polyp is removed: severe pain in your abdomen, fever, bloody bowel movements that do not get better, bleeding from your anus that does not stop, dizziness or weakness (NIDDK).

Steps that may lower your chances

Researchers do not know a sure way to prevent colon polyps, but NIDDK says you can take steps to lower your chances (NIDDK):

• get regular physical activity;
• do not smoke cigarettes, and if you do smoke, quit;
• avoid drinking alcohol;
• lose weight if you are overweight, and do not gain weight if you are already at a healthy weight (NIDDK);
• eat more fruits, vegetables and other foods with fiber, such as beans and bran cereal (NIDDK);
• eat less fatty food (such as fried foods), red meat (such as beef and pork) and processed meat (such as bacon, sausage, hot dogs and lunch meats) (NIDDK).

MedlinePlus adds that getting screened is one of the best ways to find colonic polyps, so they can be removed before they become cancerous (MedlinePlus).

Common questions

Are colon polyps cancer?

Most polyps are not cancerous, but some may turn into cancer over time (NIDDK). After removal, a polyp is tested for cancer and a pathologist sends a report to your doctor (NIDDK). NCI says most colorectal polyps are adenomas, which may turn into cancer (NCI PDQ).

Does family history raise my risk of polyps?

Yes. Having someone in your family who has had polyps or colorectal cancer is on the NIDDK list (NIDDK). If you are at higher risk for colorectal cancer, your doctor may recommend screening at a younger age, and you may need to be tested more often (NIDDK).

Can I feel a colon polyp?

Usually not. Most people with colon polyps do not have symptoms (NIDDK), which is why screening tests look for polyps in people who feel well (MedlinePlus).