A juvenile polyp is a small, round, noncancerous growth that protrudes from the inner lining of the intestine on a stalk. Despite the name, “juvenile” refers to how the polyp looks under a microscope, not to the age of the person who has one. These are the most common type of colorectal polyp in children, making up about 70% to 80% of all pediatric colorectal polyps, though adults can develop them too.
What a Juvenile Polyp Looks Like
Juvenile polyps are round, red-to-purple growths that hang from the intestinal wall on a narrow stalk, somewhat like a cherry on a stem. They appear most often in the colon and rectum, though they can also grow in the stomach and, more rarely, the small intestine.
Under a microscope, juvenile polyps have a distinctive appearance that sets them apart from other polyp types. They belong to a category called hamartomatous polyps, meaning they’re made of normal tissue types that have grown in a disorganized way. The tissue inside is typically swollen and inflamed, with fluid-filled cysts lined by mucus-producing glands. This is fundamentally different from adenomatous polyps, which involve abnormal cell growth and carry a direct risk of becoming cancerous.
Solitary Polyps vs. Juvenile Polyposis Syndrome
The distinction between a single juvenile polyp and a condition called juvenile polyposis syndrome (JPS) matters enormously, because the two carry very different levels of risk.
Solitary juvenile polyps are common in childhood. Up to 2% of children under age 10 develop one. These isolated polyps are not associated with an increased cancer risk. Once removed, they’re typically a one-time issue.
Juvenile polyposis syndrome is a different story. JPS is a hereditary condition in which multiple juvenile polyps develop throughout the gastrointestinal tract. It’s caused by inherited mutations in one of two tumor suppressor genes. The condition is rare, but it carries serious long-term consequences. Research from Johns Hopkins found that people with JPS have a relative risk of colorectal cancer roughly 34 times higher than the general population, with a cumulative lifetime risk of about 39%. The average age of cancer diagnosis in these patients is around 44.
The key diagnostic line: a child with one or two polyps almost certainly has the benign, sporadic form. Multiple polyps, especially combined with a family history of similar growths, raises the possibility of the syndrome.
Common Symptoms
The most common sign of a juvenile polyp is painless rectal bleeding, which usually shows up as bright red blood in the stool or on toilet paper. Because these polyps hang on a stalk, they can sometimes prolapse, meaning part of the polyp slips through the anus during a bowel movement. This can be alarming but isn’t dangerous.
Other symptoms depend on the size and number of polyps. A single small polyp may cause no symptoms at all and only get discovered incidentally. When multiple polyps are present, as in JPS, more significant problems can develop, including chronic bleeding that leads to anemia, diarrhea, abdominal pain, and in children, failure to grow at a normal rate due to poor nutrient absorption.
How Juvenile Polyps Are Removed
Juvenile polyps are removed during a colonoscopy through a procedure called a polypectomy. A long, flexible tube with a camera is guided through the colon, and small instruments are passed through the tube to reach the polyp. The doctor may use surgical forceps to grasp it or a wire snare to scrape it off at the base of the stalk. These tools are either heated or cooled to help immobilize the polyp during removal.
After the polyp is detached, an electrocautery device (a tool that uses electric current) seals the wound. This serves two purposes: it prevents bleeding from the removal site and destroys any small amount of polyp tissue left behind, reducing the chance of regrowth. The removed polyp is then sent to a lab for examination to confirm its type.
The procedure itself is done under sedation, and most people go home the same day. Recovery is typically quick, with minor discomfort or light bleeding for a day or two.
What Happens After Removal
For a solitary juvenile polyp, the outlook is excellent. Once removed, there’s no elevated cancer risk and no need for aggressive monitoring. Your doctor will likely recommend periodic follow-up colonoscopies to check whether new polyps have appeared, but these are precautionary.
For juvenile polyposis syndrome, follow-up is more involved. Because new polyps tend to develop over time and the cancer risk is substantial, people with JPS need regular colonoscopies throughout their lives. Screening often begins in childhood or adolescence once the diagnosis is established, and the intervals are tailored based on how quickly polyps tend to recur. Upper endoscopy (examining the stomach and upper small intestine) is also part of ongoing surveillance, since polyps in JPS aren’t limited to the colon.
Because JPS is inherited in an autosomal dominant pattern, meaning a child has a 50% chance of inheriting it if one parent carries the mutation, genetic testing and screening of family members is a standard part of managing the condition. Identifying at-risk relatives early allows surveillance to begin before polyps have a chance to become problematic.