Inclusion Criteria:

1. Male or female patients, 18 to 65 years of age.
2. If female, not of childbearing potential by reason of surgery, radiation or menopause, or of childbearing potential, but using an approved method of contraception since the last menstrual period, for example, IUD, implant, double barrier method, or oral contraceptives for at least one cycle. Females of childbearing potential must have a negative urine pregnancy test before medication is dispensed.
3. Patients must report a minimum three-month history of GERD symptoms. GERD symptoms are defined as heartburn with or without regurgitation or other associated GERD symptoms.
4. Patients must have at least 4 days with heartburn per week in each of the 2 weeks prior to screening.
5. Patients must have a no esophagitis (that is, no macroscopic erosions) on endoscopy at Screening (Grade 0 or 1 modified Hetzel-Dent), with no proton pump inhibitors (PPIs, prescription or OTC), H2 blockers (prescription or OTC) or prokinetics within 14 days, prior to the endoscopy.
6. Patients with a history of appendectomy or cholecystectomy are eligible.
7. Patients must be able to read, write and understand the language of the QOL assessment instruments (GSAS, PAGI-QOL).

Exclusion Criteria:

1. Evidence of significant hepatic, renal, respiratory, endocrine, hematologic, neurologic, psychiatric or cardiovascular system abnormalities, unless the Sponsor and Investigator agree that the nature and severity of any abnormality is unlikely to interfere with the conduct of the study, the interpretation of study results, or the health of the patient during the study.
2. Females must not be pregnant, lactating or have a positive urine B-hCG laboratory result.
3. Patients with a known or suspected history of alcohol or drug misuse within 5 years.
4. Patients who are unwilling or unable to abide by the requirements of the study or who violate the prohibitions and restrictions of the study.
5. Any condition which would make the patient, in the opinion of the Investigator or Sponsor, unsuitable for the study.
6. Patients who have participated in another investigational drug study within 30 days prior to screening or are expected to receive an investigational drug during this trial.
7. Patients with a history of allergy or sensitivity to proton pump inhibitors or to their inactive ingredients.
8. Patients who are unable or unwilling to give informed consent.
9. Patients who are unable or unwilling to complete a daily diary.
10. Patients who are unable or unwilling to return for all required study visits.
11. Patients with known gastric ulcer, duodenal ulcer, infectious or inflammatory conditions of the small or large intestine, malabsorption syndromes, obstruction, a history of gastrointestinal malignancy, or prior gastric or intestinal surgery (including vagotomy).
12. Patients who have a history of Barrett's esophagus, esophageal stricture, or pyloric stenosis.
13. Patients with a history of endoscopically-proven esophagitis (Grade 2 or more, modified Hetzel-Dent, or equivalent) any time in the past.
14. Patients with scleroderma.
15. Patients with malignancy or treatment for malignancy within the year prior to study entry, except simple excision of basal cell carcinoma.
16. Patients who are known to be HIV positive.
17. Patients with clinically relevant abnormal laboratory tests at the initial visit, including liver enzymes greater than two times the upper limit of normal.
18. Patients who have taken proton pump inhibitors (PPIs, prescription or OTC), H2 blockers (prescription or OTC) or prokinetics within 14 days, prior to Screening endoscopy, or any of these medications within 7 days prior to the single-blind placebo run-in period.
19. Patients who are unable to discontinue the use of anticholinergics, cholinergics, spasmolytics, opiates and/or sucralfate.
20. Patients who require daily use of NSAIDs (non-steroidal antiinflammatory drugs), oral steroids (20 mg/day prednisone or equivalent) or aspirin (> 325 mg/day).