Study to Evaluate the Efficacy and Safety of FEXUCLUE Tablet

Inclusion Criteria: 1. Adult aged 19 years to 75 years (on registration date) 2. Patient scheduled to administer Fexuclue tablet based on the medical judgment of investigator. 3. Patient who has not taken a treatment for gastroesophageal reflux disease within two weeks from baseline visit. 4. Patient who agreed to participate in this observation study and signed Informed Consent Form Exclusion Criteria: 1. A person who falls under the prohibition of administration according to the permission for Fexuclue Tablet * Patients with hypersensitivity to the components of Fexuclue tablet or Fexuclue tablet and a history thereof * Patients undergoing Atazanavir, Nelfinavir or Lilpivirin-containing preparations * Pregnant and lactating women * Patients with genetic problems such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabortion 2. A person who has taken a treatment for gastroesophageal reflux disease within two weeks from baseline visit. 3. In addition to the above, a person who has determined that the researcher (the doctor in charge) is not suitable for participation in this observation study