Open, Randomised, Multi-center Study of on Demand Versus Continuous Esomeprazole Treatment in Patient With GERD

Inclusion Criteria: * Symptoms suggestive of GERD, with heartburn as their predominant symptom (described as a burning feeling, rising from the stomach or lower part of the chest up towards the neck), for longer than 6 months. * Heartburn occurring for 4 days or more during the last 7 days prior to endoscopy. Or, if PPI treatment has been started within the last 7 days prior to endoscopy, then heartburn occurring for 4 days or more during the last 7 days prior to start of PPI treatment * Male or female, at least 18 years of age (for Austria, at least 19 years of age) * Have given written informed consent * Ability to read and write (literate) * 7 symptom free (from heartburn) days in the last week prior to randomisation (day of visit not included) Exclusion Criteria: * Documented esophageal mucosal break * History of esophageal, gastric or duodenal surgery, except closure and oversewing of an ulcer * Chronic or recurrent abdominal pain associated with a chronic or recurrent bowel disturbance and/or bloating, that in the opinion of the investigator is likely to be due to irritable bowel syndrome or two or more of the following criteria: * Symptoms relieved by defecation * Symptoms associated with change in frequency of stools * Symptoms associated with change in form of stools * Any significant "alarm symptoms" such as unintentional weight loss, haematemesis melaena, jaundice or any other sign indicating serious or malignant disease. * Subjects with current or historical evidence of the following diseases/conditions * Zollinger Ellison syndrome * Primary esophageal motility disorder(s) i.e. achalasia, scleroderma, esophageal spasm * Complications of GERD such as esophageal stricture, ulcer and/or macroscopic Barrett's metaplasia (longer than 3 centimetres) or significant dysplastic changes in the esophagus * Evidence of upper gastrointestinal malignancy at the screening endoscopy * Gastric and/or duodenal ulcers within the last 2 years * Malabsorption * Malignancy, or significant cardiovascular, pulmonary, renal, pancreatic or liver disease as judged by the investigator * Unstable diabetes mellitus. Stable diabetes controlled on diet, oral agents or insulin is acceptable * Cerebrovascular disease, such as cerebral ischemia, infarction, haemorrhage or embolus * Subjects using a PPI for more than 10 days in the last 28 days, prior to endoscopy * Use of PPIs for more than 5 days in the last 7 days prior to endoscopy * Subjects using daily H2-receptor antagonist, prokinetics recommended in the treatment of reflux symptoms or sucralfate during the 2 weeks prior to endoscopy and between the endoscopy and visit 1 and throughout the study * Need for continuous concurrent therapy with * NSAIDs (including selective COX II antagonists, salicylates (unless\<165 mg daily for cardiovascular prophylaxis) * anticholinergics * prostaglandin analogues * phenytoin * ketoconazole * itraconazole * warfarin and other vitamin K antagonists * Pregnancy or lactation. Women of childbearing potential must maintain effective contraception during the study period as judged by the investigator (for Austria: Women of child-bearing potential may only be included when their pregnancy status is assessed by the investigator prior to entry and then at monthly basis. For South-Africa and Spain: Women of child-bearing potential may only be included when their pregnancy status is assessed by the investigator prior to endoscopy) * Use of any other investigational compound 28 days prior to start and during the study * Requirement of an interpreter (illiterate) * Alcohol and/or drug abuse or any condition associated with poor compliance, including expected non-co-operation, as judged by the investigator * Previous participation in this study * Contra-indications to study drugs, e.g. known or suspected allergy to esomeprazole and any other constituents of the formulation. Known hypersensitivity to substituted benzimidazole