When a ventral hernia occurs, it usually arises in the abdominal wall where a previous surgical incision was made. In this area the abdominal muscles have weakened; this results in a bulge or a tear. In the same way that an inner tube pushes through a damaged tire, the inner lining of the abdomen pushes through the weakened area of the abdominal wall to form a balloon-like sac. This can allow a loop of intestines or other abdominal contents to push into the sac. If the abdominal contents get stuck within the sac, they can become trapped or “incarcerated.” This could lead to potentially serious problems that might require emergency surgery.