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Colon Polyps
Colon Polyps Overview
- What is a colon polyp?
A polyp is a small growth of cells that develops in the lining of the colon (also called the large intestine). There are many different kinds of polyps: some are benign (no cancerous potential) and some are adenomas (pre-cancerous), meaning over an extended period of time they can develop into cancer. Typically, this process takes time, on the order of multiple years. As polyps grow larger, there is a more likely chance of developing dangerous changes (called dysplasia) and if they continue to grow, they can turn into early cancer, invasive cancer or even metastatic cancer.
- Why are colon polyps so important?
Colon polyps are important because of their known relationship to colon cancer, which is the third leading cancer in the US, and the second leading cause of cancer related death.
By identifying and removing colon polyps during colonoscopy, we can prevent their progression to cancer and ultimately save lives. Since it is hard to determine the exact nature of a polyp, polyps found during colonoscopy are removed and sent to the lab for a microscopic analysis. Based on the procedure and the pathology, your GI doctor will make a recommendation on when you should come for your next colonoscopy.
- Are all colon polyps cancerous?
The two most common types of pre-cancerous colorectal polyps are “sessile serrated lesions” and “tubular adenomas”. Usually, the larger the size of the adenoma, the greater the chance that there may be cancer or pre-cancerous cells present in the polyp.
Another important term is “advanced adenoma” which is a polyp which is a little bit more dangerous. This can be because of its size (>1cm), because of the type of polyp (villous histology) or because of the presence of dangerous changes (dysplasia). These are NOT cancer, but they are more worrisome and if left untreated, they are more likely to develop into cancer.
Your gastroenterologist may make specific recommendations if you have an advanced adenoma such as more frequent colonoscopies or even discussions about screening your family members at an earlier age.
- How long does it take a colon polyp to grow into a cancer?
Current theories propose it will take about 10 years for a small adenoma to transform into a cancer. That is why the standard interval for screening colonoscopy is 10 years. However, the time interval may be shorter for patients with rare hereditary colon cancer syndromes (like familial adenomatous polyposis or hereditary non polyposis colorectal cancer) or inflammatory bowel disease.
Symptoms
- How can I tell if I have a colon polyp? Are there any symptoms?
Most polyps do not produce any symptoms, which is why screening is so important. Rarely, a polyp may cause visible blood to appear in your stool. Sometimes blood will only be detected with special testing your doctor may perform on a stool sample (hemoccult testing). Rarely, polyps may cause a change in bowel habits; if the polyp or cancer is very large it may lead to constipation, or perhaps diarrhea, though this is highly unusual.
Risk Factors
- What are the risk factors for colon polyps?
There are two types of risk factors for colon polyps: modifiable and nonmodifiable. The major non-modifiable risk factors are age, genetics and race. Nonmodifiable risk factors are out of our control, but modifiable risk factors include smoking, alcohol use, high fat diet, red meat consumption, low fiber diet, obesity and physical inactivity. The increased risk of colorectal polyps and cancer for smokers extends for at least 10 years after they discontinue smoking.
As we age, we are more likely to develop polyps. Since the colon lining is always regrowing, the older we are, the more likely the cells in the colon develop mutations.
Genetics is another risk factor and plays a major role in polyp formation. We get our genes from our parents, who may or may not have undergone colonoscopies and discovered polyps or polyp syndromes. There are specific genetic diseases which predispose patients to polyps or colon cancer. There are many types of these syndromes, and we are learning more and more about rare mutations that also play a role in polyp formation. If you have a very strong history of colon polyps or colon cancer, have colon polyps at a very young age or have a large number of colon polyps on your colonoscopy, your gastroenterologist may recommend genetic testing which would have implications for you and your family.
- Who should be checked for colon polyps?
Both men and women at average risk for colorectal cancer should begin screening for colon cancer at age 45. If you have a family history of colorectal polyps or cancer, or certain conditions such as inflammatory bowel disease and rare hereditary colon cancer syndromes you may require screening at an even earlier age or more frequent interval.
- What if my family member has colon polyps, does that mean I will also?
When one first-degree relative (parent, sibling, child) has colon polyps or colon cancer diagnosed when they are younger than 60 years old, your risk of developing colon polyps is doubled compared to someone without an affected family member. Therefore, if your father, mother, brother or sister developed an advanced adenoma polyp or cancer before the age of 60, you should begin with cancer screening at age 40, or 10 years before their diagnosis, whichever is first. If you have two first-degree relatives with polyps or colon cancer, your risk is even higher. Your doctor will likely want to perform colonoscopy at a younger age and at more frequent intervals based on your personal family history.
Screening and Diagnosis
- What tests are available to check for polyps?
Because most polyps DO NOT cause any symptoms, colorectal cancer screening for polyps is crucial for colorectal cancer prevention. There are many tests currently available to help diagnose colon polyps. The "gold standard" test that is currently available is colonoscopy, as it is the only test that is able to evaluate the entire colon lining for polyps, as well as take tissue samples and remove any polyps during the same procedure. While there are stool tests available that check for hidden blood or abnormal DNA which are currently available to help detect cancers of the colon, it is important to realize that a positive stool or blood test requires a colonoscopy in order to remove the polyp.
- What preparation is required before a colon exam?
Before your colonoscopy, you will need to clean out your colon. This is called "bowel prep." It is a very important step.
If your colon is not clean, it is hard for your doctor to see the walls clearly. Polyps can be missed. A bad prep may mean you need to repeat the test sooner.
Here are some tips:
- Read the prep instructions carefully — some diet changes start a week before the exam.
- Follow all directions closely.
- Call your clinic if you have any questions.
The better your prep, the better your exam.
- What follow-up will I need if I am diagnosed with colon polyps?
After your colonoscopy, your doctor will tell you when to come back for your next one. This is called a "surveillance" visit. The timing depends on:
- The type and number of polyps found
- How they were removed
- Your family history
- How clean your colon was during the exam
Treatment
- What is the treatment for colon polyps?
The best treatment for colon polyps is polypectomy (a painless removal of the polyp with a colonoscope at the time of colonoscopy). Sometimes a polyp is too large to remove completely in one session requiring either multiple colonoscopies, or rarely surgery to remove it completely.
- What follow-up will I need if I am diagnosed with colon polyps?
Follow-up depends on what type of polyps you have. If you have a normal colonoscopy, recommendations are to repeat the procedure in 10 years. Adenomatous polyps and sessile serrated polyps will require a repeat (surveillance) colonoscopy in an interval based on the size of the polyp and number of polyps you have. Individuals with a personal history of polyps are at increased risk for developing new polyps. It is important to remember that the quality of your bowel prep, as well as your family history, will also determine when you may require your repeat colonoscopy.
- Will colon polyps recur after they have been removed?
Yes. Even after polyps are removed, new ones can grow over time. That is why it is so important to keep up with your colonoscopy schedule.
Your primary care doctor or gastroenterologist can help you understand when you need to be screened, how often, and what kind of prep to use. There are also helpful online resources available.
Prevention
- What can I do to prevent colon polyps?
There are a few things that are within your control which can help prevent colon cancer.
First are diet and lifestyle: live a healthy life, stop smoking, reduce alcohol intake, maintain a healthy weight, eat a balanced diet low in processed foods and red meats.
The second most important thing to do is to get screened. Now we have a variety of screening tests for colon cancer, each with separate pros and cons. Talk to your doctor about which test is right for you.
Important note: Stool tests, blood tests, and CT scans are only for people at average risk. If you have had polyps before, or if colon cancer runs in your family, you should have a colonoscopy — not a stool or blood test. Ask your doctor what is right for you.
Staying up to date on colonoscopy screening recommendations is the most important thing you can do to prevent colon cancer.
Author(s) and Publication Date(s)
Monica P. Zeitz, MD, Crozer-Chester Medical Center, Upland, PA – Published May 2010.
Nimrod Deiss-Yehiely, MD, UW Hospitals and Clinics, Madison, WI – Updated August 2026.