Polyps are outgrowths of tissue from the lining of the intestine or stomach. The most common polyps look like little mushrooms with a small stalk and a bulkier end. Others are flatter and grow directly on the wall of the intestine.

What are polyps?

The lining of the intestine is normally as smooth as the inside lining of your mouth. An outgrowth of tissue from the lining of the intestine is referred to as an intestinal polyp.

Polyps may grow out of the lining of the small and/or large intestine or stomach. Most commonly, polyps are shaped like a mushroom, with a narrow stalk that connects the bulkier end to the intestinal wall. Other polyps are flatter and grow directly on the wall of the intestine. The size of polyps may vary from under two milimeters (less than one-tenth of an inch) to over one inch in diameter. There are two general types of polyps including adenomatous and hamartomatous polyps. The type of polyp is based on what the appearance is under the microscope. Adenomatous polyps are typically the type of polyp seen in adults and these need to be evaluated for possible malignant change. Hamartomatous polyps are the type of polyp usually found in children and these rarely pose a concern of malignancy.

How common are they?

A polyp may be found in the large intestine in about 1-2 percent of children. The most common type of polyp is a juvenile polyp accounting for more than 95 percent of polyps found in children. These are mostly found in children under 10 years old, and especially in those 2-6 years of age. The majority of juvenile polyps are solitary (1-5 polyps) and are found mostly in the let side of the colon. Some children inherit genes that make them more likely to develop many polyps (referred to as polypossi syndromes). Some of these polyposis syndromes can result in hamartomatous polyps while others give rise to adenomatous polyps.

These syndomes include familiar adenomatous polyposis, juvenile polyposis syndrome, Peutz-Jeghers syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Cowden disease.

Families are usually asked if other members have had polyps to determine if it is likely the child has one of these inherited conditions.

What are the symptoms of polyps?

Children with polyps usually pass blood in the stools. This bleeding does not cause any pain for the child. With small amounts of bleeding over months, some children can develop iron-deficiency anemia and have symptoms of this. Bleeding may not happen with every bowel movement, and tends to recur over weeks to months. It is rare for children to have other symptoms, but when they do they can have: crampy abdominal pain, diarrhea with mucus, or even prolapse of the polyp (where the polyp will partially stick out of the rectum while still being attached to the wall of the large intestine).

How is the diagnosis made?

If a child presents with a prolapse of a polyp, the diagnosis is easy to make. For most cases, a child will be referred to a pediatric gastroenterologist for passing blood out of the lower part of the large intestine (rectal bleeding). Your doctor will recommend a colonoscopy where the doctor looks directly into the large intestine with a narrow bendable tube mounted with a camera and a light to help find the source of bleeding. When a polyp is seen, the gastroenterologist will use a small grasping instrument that fits inside the colonoscope to grab the entire polyp and remove it. The polyp is then sent to the pathologist, who will look at it under the microscope to determine what kind it is. The gastroenterologist will look at the entire large intestine with the colonoscope to make sure there are no other polyps. Usually, all polyps are removed (unless there are very many or it is unsafe to do so).

If the child is found to have a particular set of findings (or syndrome), a diagnosis of one of the above-mentioned polyposis syndromes may be made. For some of these, special genetic tests can be performed with a blood test to confirm the diagnosis.

What are potential complications of polyps?

Polyps rarely may bleed a large amount, especially if they break off at their stalk (autoamputate). They may cause a special kind of blockage of the intestines called intussusception. If a child is found to have a single juvenile polyp, they usually do not need to have another colonoscopy. Children that have several polyps, or children whose families have special polyposis syndromes, may need to undergo regular colonoscopies for surveillance as new polyps may form and need to be removed. The significance of polyps in most children is not the same as in adults (for whom there is a high concern for cancer). For children with inherited conditions with several polyps, there may be an increased risk of cancer developing from a polyp. Fortunately, for the majority of children with a solitary juvenile polyp, there is no increased risk of cancer.

Updated May 2015

North American Society for Pediatric Gastroenterology, Hepatology and Nutrition
The Association of Pediatric Gastroenterology and Nutrition Nurses
North American Society for Pediatric Gastroenterology, Hepatology and Nutrition Foundation
The NASPGHAN Council For Pediatric Nutrition Professionals
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