There are several reasons for the protruding belly button: 1. It is possible that the residual end left when the umbilical cord was cut at birth is relatively long, thus causing the belly to protrude. There are usually no obvious symptoms of discomfort and no special treatment is needed. 2. It is possible that there is inflammation inside the belly, commonly known as umbilicitis. It is possible that the protrusion is a strong inflammation, which is manifested by the redness, swelling and pain around the local tummy. If there is a purulent infection, pressure on the belly button or the skin around the belly can appear volatile. 3, it may be ascites, such as chronic liver disease, cirrhosis of the liver leads to a lot of ascites inside the abdominal cavity, which leads to the belly button protruding outward.