Acid reflux, also known as gastroesophageal reflux disease (GERD), is a very common minor health problem, faced by many people. This is caused due to the improper working of a valve-like opening, called the lower esophageal sphincter (LES), which is a circular muscle band. This sphincter connects the esophagus and the stomach. The stomach contains cells that secrete acid to digest the food, and to protect the stomach lining from these acids, there is a protective coating of the mucus cells. The esophagus, however, has very less protection from these acids as compared to the stomach.