A disease that is commonly known as Gastroesophageal Reflux Disease or GERD is Acid Reflux. To describe this, it is the condition in which the stomach’s liquid content refluxes in the esophagus. Damage and inflammation in the lining of esophagus can be caused by this liquid. Pepsin and acid can be found in the liquid that is refluxed and this is produced by the stomach. Pepsin refers to the enzyme which starts the digestion of the proteins found in our stomach. The regurgitated liquid can also contain bile that backs-up from the duodenum which attaches the small intestines to the stomach. The most damaging ingredient in acid reflux is acid.