Consecutive patients aged 18-65 years who go to the gastroenterology clinic presented with upper gastrointestinal discomfort would be included. All patients underwent upper endoscopy or an ambulatory 24-h pH(Potential Of Hydrogen) monitoring.Pathologic esophageal acid reflux was defined as the percentage total time for which a pH value < 4 was >4.2 % in the distal esophagus. Then, patients were treated with esomeprazole 20 mg twice daily for 28 days. The symptom scores were measured by the frequency score multiplied by the severity scores of the predominant symptom before and at the end of the treatment, and the " PPI test " was defined as positive if the overall scores of the predominant dyspeptic symptom in the fourth week decreased by >50 % compared with those of the baseline.