Double-blind Comparative Study of E3810 Tablets (10 or 20 mg b.i.d.) to Evaluate Efficacy and Safety in Patients With Refractory Reflux Esophagitis

Inclusion Criteria: * Patients who have mucosal breaks (erosions, ulcers) on endoscopy and are diagnosed with reflux esophagitis. * Proton Pump Inhibitor standard dose-resistant reflux esophagitis. * Patients who are 20 years and older when informed consent is obtained. Exclusion Criteria: * Patients with a concurrent severe illness, serious heart disease, comorbid severe disease such as hematology, kidney disease, or liver disease. * Patients with malignancy. * Patients who are taking another trial drug or the interval between the end of treatment and screening is less than 12 weeks.