Background:The clinical spectrum of symptomatic polyps and the frequency of familial polyposis is not well defined in children. In the present study, a series of children with juvenile polyposis coli (JPC) and non‐JPC polyps were studied.Methods:Children with symptomatic colonic polyps and negative family history of polyps were ascertained by review of endoscopic records. Juvenile polyposis coli was defined as 10 or more juvenile polyps or any juvenile polyp in a relative of an index case of JPC. Polyps were tested for Ki‐ras mutations, p53 overexpression, and aneuploidy.Results:Seventy‐eight children (age range, 0.4‐18 years) were identified, all evaluated for lower gastrointestinal bleeding. Nine (12%) had JPC, 66 (84%) had isolated juvenile polyps, and 3 (4%) had other types of polyps. The JPC and non‐JPC groups were similar in age (p = 0.4) and symptom duration (p = 0.3). The JPC group had more polyps (p = 0.0001), and greater likelihood of anemia (p = 0.01), polyps with adenomatous change (p = 0.03), and right‐colon polyps (p = 0.001). In three of eight JPC families, polyps were identified in asymptomatic first‐degree relatives. No abnormalities in Ki‐ras, p53, or aneuploidy were identified.Conclusions:Juvenile polyposis coli is common in children with symptomatic polyps, and is associated with anemia, right‐colon polyps, and adenomas. The risk of polyps and of colorectal cancer in relatives of persons with JPC requires further study.