What Are Polyps In The Colon? Key Information

Finding out you have a colon polyp is common. About 1 in 3 adults over age 50 has at least one, though most never know it because polyps usually cause no symptoms at all. A colon polyp is a small growth of tissue that forms on the inner lining of the large intestine. Most are harmless, but some can slowly turn into colon cancer over many years, which is why doctors remove them when they find them.

What Are Polyps In The Colon?

A colon polyp is an extra clump of cells that grows on the lining of the colon or rectum. It sticks out from the surface like a small bump, a mushroom, or a tiny raised patch. Doctors call these growths “polyps.”

Polyps start when cells in the colon lining divide more than they should. Over time, this extra cell growth can form a visible mass. The colon is about 5 feet long, and polyps can appear anywhere along that length, from the beginning of the large intestine to the rectum.

What makes polyps worth paying attention to is simple. Most stay harmless for a person’s whole life. A small share of them, though, can change over years into cancer. The exact number of polyps that become cancer is hard to pin down because the process takes so long and depends on the type. The important point is that polyps are the usual starting point for the most common kind of colon cancer.

This is also why colon cancer screening works. When a doctor removes a polyp during a colonoscopy, that growth can no longer turn into cancer. Screening does not just find cancer early — it can stop some cancers from forming in the first place.

What Are The Different Types Of Colon Polyps?

Not all polyps are alike. The type matters because it affects the chance that a polyp could become cancer. Doctors identify the type by looking at tissue under a microscope after removal.

The two main groups are neoplastic polyps and non-neoplastic polyps. Neoplastic polyps have the potential to become cancer. Non-neoplastic polyps generally do not.

Within neoplastic polyps, the most common type is the adenoma. Adenomas are the growths doctors worry about most, because they are the ones most likely to turn into cancer over time. A smaller group of neoplastic polyps are called sessile serrated lesions. These are flatter and harder to spot during a colonoscopy, and they also carry a risk of becoming cancer.

Non-neoplastic polyps include hyperplastic polyps and inflammatory polyps. Hyperplastic polyps are common, especially in the lower part of the colon, and are usually harmless. Inflammatory polyps often show up in people with long-term inflammation of the colon, such as inflammatory bowel disease.

Polyps are also described by their shape:

• Sessile — flat, growing directly out of the colon wall
• Pedunculated — attached by a stalk, like a mushroom

Shape matters mainly for how easily a doctor can remove the polyp, not for whether it is dangerous. A flat polyp can be harder to see and remove than one on a stalk.

What Causes Colon Polyps?

There is no single cause. Polyps result from changes in the DNA of cells lining the colon. These changes build up over years and are influenced by both genetics and lifestyle.

Age is the strongest factor. Polyps become far more common as people get older. This is why screening generally begins around age 45 for most adults at average risk, though exact recommendations can vary and are worth confirming with a doctor.

Other factors linked to a higher chance of polyps include:

• A family history of polyps or colon cancer
• Certain inherited conditions, such as familial adenomatous polyposis and Lynch syndrome
• Inflammatory bowel disease, including ulcerative colitis and Crohn’s disease
• Smoking
• Heavy alcohol use
• Diets high in red and processed meat and low in fiber
• Obesity and low physical activity
• Type 2 diabetes

These are associations, not guarantees. Having one or more of these factors does not mean a person will develop polyps, and many people with polyps have none of them.

Some inherited conditions raise risk sharply. Familial adenomatous polyposis causes hundreds to thousands of polyps to form, often by the teenage years, and carries a very high lifetime risk of colon cancer if the colon is not removed. These conditions are rare, but they are why family history is taken seriously.

What Are The Symptoms Of Colon Polyps?

Most colon polyps cause no symptoms. This is the single most important fact about them. A person can have polyps for years and feel completely normal.

When symptoms do appear, they usually mean a polyp has grown large. Possible signs include:

• Blood in the stool, or stool that looks dark and tarry
• A change in bowel habits lasting more than a week, such as constipation or diarrhea
• Stools that are narrower than usual
• Abdominal pain or cramping
• Feeling that the bowel has not fully emptied
• Unexplained iron-deficiency anemia

These symptoms are not specific to polyps. They can come from many other conditions, some minor and some serious. Blood in the stool, for example, is more often caused by hemorrhoids than by polyps, but it should never be assumed to be harmless without a doctor’s evaluation.

Because polyps usually cause no symptoms, waiting for signs to appear is not a reliable way to catch them. Screening finds polyps before they cause any trouble.

How Are Colon Polyps Found And Removed?

Colonoscopy is the main way polyps are found and removed. A doctor passes a thin, flexible tube with a camera through the rectum and into the colon. If a polyp is seen, it is usually removed during the same procedure using a small wire loop, forceps, or other tools.

Other screening tests can detect polyps or signs of them, but they work differently:

• Stool tests check for hidden blood or altered DNA in the stool. They can suggest a problem but do not remove polyps.
• CT colonography (virtual colonoscopy) uses imaging to look at the colon. It can find larger polyps but cannot remove them.
• Flexible sigmoidoscopy examines only the lower part of the colon.

If a stool test or imaging test suggests a polyp, a colonoscopy is usually needed to remove it. A colonoscopy is the only test that both finds and removes polyps in one step.

After removal, the polyp is sent to a lab. A pathologist examines it under a microscope and reports the type, size, and whether any cells look abnormal. That report guides how soon the next colonoscopy should be scheduled.

How Often Should You Be Screened After Polyps Are Found?

When the next colonoscopy should happen depends on what was found. A single small, low-risk polyp leads to a longer interval before the next test. Multiple polyps, larger polyps, or polyps with concerning features lead to a shorter interval.

For most people at average risk with no polyps found, follow-up is typically around 10 years. When one or two small, low-risk adenomas are removed, the interval is often around 7 to 10 years. With more or higher-risk polyps, the recommended interval is shorter, sometimes 3 to 5 years.

These are general patterns, not fixed rules. The exact timing is set by the doctor based on the pathology report, the number and size of polyps, and the person’s overall risk. Anyone who has had polyps should ask their doctor when the next screening is due rather than assuming a standard 10-year gap.

Regular screening is the most effective step a person can take. Removing polyps before they become cancer is one of the clearest examples in medicine of preventing cancer rather than just treating it.

Can Colon Polyps Be Prevented?

No lifestyle change can guarantee that polyps will not form. But some habits are linked to a lower chance of developing them.

Evidence suggests that a diet rich in fiber, fruits, and vegetables, along with regular physical activity and avoiding smoking, is associated with lower risk. Limiting red and processed meat and moderating alcohol also appear helpful. These are associations drawn from population studies, and they do not prove that any single change prevents polyps in a given person.

What is well established is that screening prevents cancer by finding and removing polyps. No diet or supplement has been shown to replace screening. Some studies have looked at whether certain nutrients or medications reduce polyp formation, but results have been mixed, and none of these approaches is a substitute for regular screening.

For people with inherited conditions that cause many polyps, prevention looks different. These cases often require more frequent screening, sometimes starting in childhood or the teen years, and in some situations surgery to remove the colon. These decisions are made with specialists.