Colorectal polyps
Intestinal polyps; Polyps - colorectal; Adenomatous polyps; Hyperplastic polyps; Villous adenomas; Serrated polyp; Serrated adenoma; Precancerous polyps; Colon cancer - polyps; Bleeding - colorectal polyps
A colorectal polyp is a growth on the lining of the colon or rectum.
There are 3 basic tests for colon cancer; a stool test (to check for blood), sigmoidoscopy (inspection of the lower colon), and colonoscopy (inspection of the entire colon). All 3 are effective in catching cancers in the early stages, when treatment is most beneficial.
The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.
Causes
Polyps of the colon and rectum are most often benign. This means they are not a cancer. You may have one or many polyps. They become more common with age. There are many types of polyps.
Adenomatous polyps are a common type. They are gland-like growths that develop on the mucous membrane that lines the large intestine. They are also called adenomas and are most often one of the following:
- Tubular polyp, which protrudes out in the lumen (open space) of the colon
- Villous adenoma, which is sometimes flat and spreading, and is more likely to become a cancer
When adenomas become cancerous, they are known as adenocarcinomas. Adenocarcinomas are cancers that originate in glandular tissue cells. Adenocarcinoma is the most common type of colorectal cancer.
Other types of polyps are:
- Hyperplastic polyps, which rarely, if ever, develop into cancer
- Serrated polyps, which are less common, but may develop into cancer over time
Polyps that are 1 centimeter (cm) or larger have a higher cancer risk than polyps smaller than 1 cm. Risk factors include:
- Age
- Family history of colon cancer or polyps
- A type of polyp called villous adenoma
A small number of people with polyps may also be linked to some inherited disorders, including:
- Familial adenomatous polyposis (FAP)
- Gardner syndrome (a type of FAP)
- Juvenile polyposis, a disease that causes many benign growths in the intestine, usually before 20 years old
- Hereditary non-polyposis colorectal cancer (HNPCC), also called Lynch syndrome, a disease that raises the chance of many types of cancer, including in the intestine
- Peutz-Jeghers syndrome, a disease that causes intestinal polyps, usually in the small intestine and usually benign
Colon cancer is one of the leading causes of cancer-related deaths in the United States. The good news is that early diagnosis often leads to a complete cure. Let's talk today about colorectal polyps. A colorectal polyp is a growth of tissue that sticks out of the lining of the colon or rectum. Polyps are benign, meaning that they're not cancer and they won't spread, but over time certain types can develop into cancer. One of these types is called adenomatous polyps. These are known as pre-cancerous polyps. Polyps bigger than 1 centimeter have a greater cancer risk than polyps under 1 centimeter. Risk factors include your age, family history of colon cancer or polyps, and a type of polyp called villous adenoma. Polyps may also be associated with a few genetically inherited disorders. So, how do you know if you have polyps? Well, usually, you won't have any symptoms. Some people, however, may feel abdominal pain (rarely), have blood in their stool, and feel fatigue from losing blood over time. Usually, a routine colon cancer screening will reveal a polyp through tests called barium enema, colonoscopy, sigmoidoscopy, or virtual colonoscopy. So, what do you do about polyps? Well, because colorectal polyps can develop into cancer, your doctor should remove them. Usually, polyps will be removed during a colonoscopy. If your doctor finds that you have adenomatous polyps, be aware that you may get new polyps in the future. Your doctor will recommend that you have a follow-up colonoscopy in 1 to 10 years, depending upon your age and general health, the number of polyps the doctor found, the size and characteristic of the polyps, and if cancer was found. The good news is that your outlook is excellent if your doctor removes colorectal polyps and performs routine surveillance and screening.
Symptoms
Polyps usually do not have symptoms. When present, symptoms may include:
- Blood in the stools
- Change in bowel habit
- Fatigue caused by losing blood over time
Exams and Tests
Your health care provider will perform a physical exam. A large polyp in the rectum may be felt during a rectal exam.
Most polyps are found with the following tests:
- Barium enema (rarely done)
- Colonoscopy
- Sigmoidoscopy
- Stool test for hidden (occult) blood
- Virtual colonoscopy
- Stool DNA test
- Fecal immunochemical test (FIT)
Treatment
Colorectal polyps should be removed because some can develop into cancer. In most cases, the polyps may be removed during a colonoscopy.
For people with adenomatous polyps, new polyps can appear in the future. You should have a repeat colonoscopy, usually 1 to 10 years later, depending on:
- Your age and general health
- Number of polyps you had
- Size and type of the polyps
- Family history of polyps or cancer
In rare cases, when polyps are very likely to turn into cancer or too large to remove during colonoscopy, the provider will recommend a partial colectomy. This is surgery to remove part of the colon that has the polyps.
Outlook (Prognosis)
The outlook is excellent if the polyps are removed. Polyps that are not removed can develop into cancer over time.
When to Contact a Medical Professional
Contact your provider if you have:
- Blood in a bowel movement
- Change in bowel habits
Prevention
To reduce your risk of developing polyps:
- Eat foods low in fat and eat more fruits, vegetables, and fiber.
- Do not smoke and do not drink alcohol in excess.
- Maintain a normal body weight.
- Get regular exercise.
Your provider can order a colonoscopy or other screening tests:
- These tests help prevent colon cancer by finding and removing polyps before they become cancer. This may reduce the chance of developing colon cancer, or at least help catch it in its most treatable stage.
- All adults should begin one of these tests at age 45.
Taking aspirin, naproxen, ibuprofen, or similar medicines may help reduce the risk for new polyps. Be aware that these medicines can have serious side effects if taken for a long time. Side effects include bleeding in the stomach or colon and heart disease. Talk with your provider before taking these medicines.
References
Centers for Disease Control and Prevention. What can I do to reduce my risk of colorectal cancer?
Garber JJ, Chung DC. Colonic polyps and polyposis syndromes. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 126.
National Cancer Institute website. Colorectal cancer prevention (PDQ) - health professional version.
National Comprehensive Cancer Network website. NCCN clinical practice guidelines in oncology (NCCN guidelines): colorectal cancer screening. Version 1.2023 - May 17, 2023.
Patel SG, May FP, Anderson JC, et al. Updates on age to start and stop colorectal cancer screening: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer. Gastrointest Endosc. 2022;95(1):1-15. PMID: 34794803
Qaseem A, Crandall CJ, Mustafa RA, Hicks LA, Wilt TJ. Clinical Guidelines Committee of the American College of Physicians, et al. Screening for colorectal cancer in asymptomatic average-risk adults: a guidance statement from the American College of Physicians. Ann Intern Med. 2019;171(9):643-654. PMID: 31683290
US Preventive Services Task Force website. Final recommendation statement. Colorectal cancer: screening.
Version Info
Last reviewed on: 5/2/2023
Reviewed by: Michael M. Phillips, MD, Emeritus Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Internal review and update on 02/10/2024 by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
