2. Pregnant, nursing, and childbearing potential women who is unwilling to effective contraception; for example, oral contraceptives, hormonal methods, placement of an intrauterine device (IUD) or intrauterine system (IUS), barrier methods (i.e., condom or occlusive cap with spermicidal foam/gel/film/cream/ suppository), male sterilization, and true abstinence 3. Presence of family history of GI malignancy or alarm features suggested malignancy - e.g. Unintentional weight loss (more than 10% of body weight in recent 6 months), GI bleeding 4. Patients consuming regular Aspirin or NSAIDs (except low-dose Aspirin at a dose of 325 mg/day or less for cardiovascular prophylaxis) 5. History of erosive esophagitis, peptic ulcer disease within 1 year prior to the screening 6. History of gastrointestinal (GI) malignancy, primary esophageal motility disorder, documented upper GI surgery 7. Patients with any hepatobiliary or pancreatic diseases 8. Patients with severe depression, anxiety, or other psychological disorder 9. Patients with any terminal disease 10. Presence of irritable bowel syndrome (Rome III criteria) or inflammatory bowel disease (IBD) 11. Necessary to have a continuous concomitant treatment with sucralfate, quinidine, warfarin, phenytoin, bisphosphonates, methotrexate, ketoconazole, fluconazole, itaconazole, diazepam, anti-cholinergics, H2RAs, PPIs (except study drug), prokinetics, and/or NSAIDs (except topical use of NSAIDs; in systemic NSAIDs ≤2 days/week) 12. Use of PPIs (except study drug), H2RAs, prokinetics, antibiotics (except topical use), misoprostol, or bismuth compounds within 1 week prior to the screening, and who were taking antibiotics used to eradicate Helicobacter pylori within 4 weeks prior to the screening 13. Unable to communicate in English, Malay, or Mandarin 14. Other conditions determined by the investigator to be inappropriate for this clinical study Duration of treatment: 8 weeks Number of subjects: Ninety-three patients per each group with 90% power at the 0.05 significance level were used. Considering 10% drop-out rate, total of 208 patients (104 patients per each group) will be enrolled in the study.