Hernia (Umbilical/Inguinal)

What is a hernia?
A hernia occurs when a section of intestine protrudes through a weakness in the abdominal muscles. A soft bulge is seen underneath the skin where the hernia has occurred.

In babies, a hernia usually occurs in one of two places:

Around the belly button

In the groin area

A hernia that occurs in the belly button area is called an umbilical hernia.

A hernia that occurs in the groin area is called an inguinal hernia.

What causes a hernia?
A hernia can develop in the first few months after the baby is born because of a weakness in the muscles of the abdomen. Inguinal and umbilical hernias happen for slightly different reasons.

What is an inguinal hernia?
As a male fetus grows and matures during pregnancy, the testicles develop in the abdomen and then move down into the scrotum through an area called the inguinal canal. Shortly after the baby is
born, the inguinal canal closes, preventing the testicles from moving back into the abdomen. If this area does not close off completely, a loop of intestine can move into the inguinal canal through the
weakened area of the lower abdominal wall, causing a hernia.

Although girls do not have testicles, they do have an inguinal canal, so they can develop hernias in this area as well. Inguinal hernias do not occur as frequently among females as they do in males.

What is an umbilical hernia?
When the fetus is growing and developing during pregnancy, there is a small opening in the abdominal muscles so that the umbilical cord can pass through, connecting the mother to the fetus. After birth,
the opening in the abdominal muscles closes as the baby matures. Sometimes, these muscles do not meet and grow together completely, and there is still a small opening present.
A loop of intestine can move into the opening between abdominal muscles and cause a hernia.

https://www.stanfordchildrens.org/en/topic/default?id=hernia-umbilicalinguinal-90-P02422