It is a condition in which the stomach contents go back to the esophagus, the tube that goes from the mouth to the stomach. This can cause gastric acidity and irritate the esophagus.

The Gastroesophageal reflux is due to changes in the mechanisms that naturally prevent that stomach contents go back to the esophagus. The causes may be a failure of the lower esophageal sphincter or a transient lower esophageal sphincter relaxation that consists of an impaired expulsion of gastric reflux from the esophagus or a hiatus hernia.