Most juvenile polyps have a peduncle, but only very small ones lack a stalk. They are slender and without muscle. The size of polyps is usually 1-3 millimeters. Some less than 1 millimeter in size have spherical or nodular heads. They also have splits. Most of them are red and often accompanied by ulceration or superficial ulcers. On a histological level, polyps are mucosal. The lesions include expansion in the basal layer, mucus filling, cystic dilatation, and inflammatory cell glands. They contain well-differentiated mucosal cells, significantly widened matrix, and a large amount of connective tissue. They also contain a large number of blood vessels and inflammatory cells. Sometimes, a small amount of smooth muscle cells are found due to gland expansion and rupture. There may be a plasmid-induced foreign body giant cell reaction.