Umbilical hernia is when small intestine or fatty tissue pushes anteriorly-out through the abdomen close to your belly button. •Cause: The weakness may be due to underdeveloped connective tissue or a muscle of the abdomen. In adults, too much abdominal pressure can cause an umbilical hernia. Possible causes in adults include: 1) Obesity. 2) Multiple pregnancies. 3) Fluid in the abdominal cavity (ascites). 4) Previous abdominal surgery. 5) Chronic peritoneal dialysis. •Treatment: umbilical hernia can be treated with surgery to push the bulge back into place and strengthen the weakness in the abdominal wall. The operation may be recommended for your child if the hernia is large or hasn't disappeared by the time they reach four or five years old.