Investigators will conduct a comparative effectiveness study of genotype-supported vs. conventional PPI dosing. Patients presenting with Gastroesophageal Reflux Disease (GERD) or dyspepsia symptoms and either 1) being initiated on proton pump inhibitor (PPI) therapy or 2) with continued symptoms on current PPI therapy will be recruited from gastroenterology clinics and randomized to a genotype-supported versus conventional PPI therapy management strategy.