An umbilical polyp is a firm, red or pink bump at the belly button (navel). It's visible after a newborn's umbilical stump dries up and falls off. The polyp is made of tissue found in the intestinal lining. It develops while the fetus is still forming in the uterus.
These polyps can look like another type of bump called an umbilical granuloma. But umbilical polyps are often bigger. They also require different treatment. They are also less common.