GERD (Gastroesophageal reflux disease) is a digestive dysfunction in which lower esophageal sphincter (LES) the ring of muscle between esophagus and stomach is affected. Stomach and esophagus combined to form gastroesophagus. So, therefore, gastroesophageal reflux is the flow back of stomach’s material into an esophagus. When a person eats food, it passes through the esophagus to the stomach. LES or lower esophageal sphincter opens up to allow food to go into stomach and close to prevent backflow. Gastroesophageal reflux happens when LES or Lower esophageal sphincter is weak or relaxes oddly, which brings about the backflow of food into the esophagus.