The navel is a scar formed due to the closing of the orifice through which the element of the umbilical cord pass.
A week or two after birth the umbilical cord falls and the umbilical vessels close.
In most cases the treatment consists in waiting for the spontaneous closing. There is no need for navel bandages, abdominal supporters, etc.
The patient will be sent to the surgeon for surgical correction only if it persists in children over 2 years old, if there is pain in the area (probable pincement of the omentum, layer covering the abdominal cavity) or if there are signs of obstruction (not very frequent) and also due to aesthetic and preventive reasons (because it can get bigger in size during pregnancy).