Omeprazole  is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease (PUD), gastroesophageal reflux disease (GORD/GERD),laryngopharyngeal reflux (LPR) and Zollinger-Ellison syndrome. It is also used to promote healing of erosive esophagitis (damage to your esophagus caused by stomach acid). Omeprazole may also be given together with antibiotics to treat gastric ulcer caused by infection with helicobacter pylori (H. pylori).