Short-term treatment of gastroesophageal reflux disease (GERD) in patients with irritation and swelling of the esophagus when medicine cannot be taken by mouth. It is also used to reduce the risk of bleeding ulcers after a certain procedure (endoscopy). It may also be used for other conditions as determined by your doctor. Esomeprazole is a proton pump inhibitor (PPI). It works by decreasing the amount of acid produced in the stomach.