An umbilical hernia occurs when weakened muscles around the belly button allow tissues in the abdomen to push through. The umbilical cord passes through the abdominal muscles, therefore it is an area where a hernia can develop. Due to the small size of an umbilical hernia, it is usually only the peritoneum that protrudes through the muscle wall, however in more severe cases, it is also possible for part of the intestine to push through.
Umbilical hernias are most commonly present from birth, although they can occur in adults after having surgery. Normally, an umbilical hernia will heal itself when the muscles strengthen, however for some children surgery will be required. The surgery is typically carried out under a general anaesthetic. The surgeon will make a small incision under the belly button and the surgeon can then return the hernia sac back to its normal position. For larger hernias, a mesh will be inserted to cover the hole in the muscle and reinforce the weakened area.