An inguinal hernia is an abnormal bulge, or protrusion, that can be seen and felt in the groin area (the area between the abdomen and the thigh). An inguinal hernia develops when a portion of the intestine (bowel), along with fluid, bulges through the muscle of the abdominal wall.

Inguinal hernias in children result from a weakness in the abdominal wall that is present at birth. The bulge in the groin might only be noticed when the child is crying, coughing, or straining during a bowel movement, or it might appear to be larger during these times. Of the newborns who have inguinal hernias, 90 percent are boys.

Hernias usually need to be surgically repaired to prevent intestinal damage and further complications. The surgery can usually be done as a day case although infants less than 46 weeks post conception usually require an overnight stay in hospital.

Occasionally, if the weakness or defect in the abdominal wall is small, this can result in a portion of intestine becoming trapped. This is called an incarcerated hernia and can cause problems such as severe pain, nausea, vomiting, or absence of bowel movements. Larger abdominal wall defects allow the intestine to move freely in and out of the weakened abdominal wall and do not tend to be as painful.