The purpose of this study is to define the endoscopic findings of minimal change that is significant to clinical significant reflux esophagitis. Through this, the investigators want to estimate the applicability of minimal change findings of reflux esophagitis to the clinic.

Inclusion Criteria:

• Age ≥ 20 years old patients who consent to revealing their medical information and be able to respond to questionnaires regarding the symptom.
• Patients who had shown the reflux esophageal minimal change in the endoscopic finding: the reflux esophagitis

Exclusion Criteria:

• Patients who had shown the mucosal break or barrett esophagus at gastric mucosal barrier or lower oesophagus in endoscopic findings
• Patient with a diagnosis of gastroesophageal reflux disease and who have received medication treatment
• Patient who had received H2-receptor antagonists, prostaglandin, PPI, NSAIDs or aspirin, high dose steroid and anticoagulants for at least 5 consecutive days in the 4-week period immediately preceding the diagnostic endoscopy
• Patients with a history of operation due to gastrointestinal disease, malignancy, alcoholism, pregnancy (in female), breast feeding (in female) or systemic disease

Patients who had shown the reflux esophageal minimal change in the endoscopic finding