GERD is usually caused by changes in the barrier between the stomach and the esophagus, including abnormal relaxation of the lower esophageal sphincter, which normally holds the top of the stomach closed, impaired expulsion of gastric reflux from the esophagus, or a hiatal hernia. These changes may be permanent or temporary. The treatments for GERD include lifestyle modifications, medications, and possibly surgery. Initial treatment is frequently with a proton-pump inhibitor such as omeprazole