Hiatal hernia Diagnosis and treatment: When the hiatus allows the LES and part of the stomach to protrude upward into the chest cavity, the result is a hiatal hernia. This condition is found in up to 50% of the population over the age of 50. If no symptoms are associated with it, treatment is usually not required. Frequently, however, patients with hiatal hernia also suffer from the symptom of heartburn. Heartburn is the result of stomach acid reflux into the esophagus. This occurs because of a failure of the LES to close properly. When this happens, stomach contents (which usually contain acid) are pushed back up into the esophagus, causing irritation and the burning sensation commonly called “heartburn”. Regurgitation of food and bile may also occur. Heartburn can also occur without hiatal hernia.