 approximately 20 of patients taking first generation proton pump inhibitors PPIs are taking more than the standard approved dose. This dosing is required to attain adequate control of the gastric and intraesophageal pH in order to affect the desired clinical improvement. It is recognized that the b.i.d dosing strategy increases the intragastric pH control of 4 from approximately 12 hours to almost 16 hours. The refinement of the S isomer of omeprazole Nexiumhas led to a way to more effectively control acid exposure. Comparative trials with all the PPIs have shown significantly greater pH control of 4 and head to head comparisons as well as a recent crossover study. One study suggests that Nexium dosing contains approximately 16.5 hours of a pH control of 4. Conceivably, this duration of pH control suggests that b.i.d. dosing of other PPIs might be avoided. Furthermore, it suggests that patients currently taking b.i.d. PPIs might be successful candidates for conversion to q.d. Nexium. This would provide a considerable cost implication to health care plans and for patients who are responsible for paying for their PPI therapy. To date, esomeprazole has not been studied in comparison to b.i.d. dosing with other PPIs. There is pharmacologic evidence to suggest, however, that it is comparable. In this proposed study, we believe that by beginning with patients who were well controlled should make for a cleaner definition and a higher likelihood to demonstrate efficacy. 