Efficacy/Safety of Lansoprazole in Patients With Frequent Heartburn

Inclusion Criteria: 1. Experiencing heartburn at least 2 days per week over the past month. 2. Having heartburn that responds to heartburn medication. 3. Be willing to discontinue the use of heartburn treatment for 7 days prior to inclusion in the study. Exclusion Criteria: 1. Having history of erosive esophagitis or gastroesophageal reflux disease diagnosed by a physician and confirmed by testing (endoscopy). 2. Be unwilling to take only the study medication, and antacid provided as a rescue medication for relief of acute heartburn during the study. Other protocol-defined inclusion or exclusion criteria may apply.