A hiatal hernia is different from hernias of the abdominal wall. The hiatus is one of the openings in the diaphragm, which is a muscular membrane that separates the chest and abdominal cavities. The esophagus passes through the hiatus. The junction between the esophagus and the stomach contains the lower esophageal sphincter. The lower esophageal sphincter is a condensation of circular muscles that act as a valve to allow food to pass into the stomach but doesn't allow it to reflux back into esophagus to produce heartburn symptoms. When the sphincter is herniated into the chest, it cannot function effectively. Gastroesophageal reflux disease (GERD) treatment includes lifestyle and diet modifications, acid suppressing medications and surgical interventions, particularly in cases of hiatal hernia.
For additional information about Anti-Reflux (GERD) Surgery: https://www.sages.org/publications/patient-information/patient-information-for-laparoscopic-anti-reflux-gerd-surgery-from-sages/