19th century illustration of a umbilical congenital hernia and umbilical cord. A hernia is a protrusion of an organ outside of its normal cavity. In this case, part of the gut is pressing through the umbilicus (navel), causing it to bulge. Umbilical hernias in babies tend to resolve spontaneously, and therefore do not usually require any surgical treatment. Artwork published in Artwork published in New Dictionary of Practical Medicine and Surgery, 1877.