Verification Study on Lafutidine in Mild Reflux Oesophagitis - Double Blind Controlled Study With Famotidine -

Inclusion Criteria: Age 20 and over (at the time of consent given) Gender and inpatient or outpatient: Irrelevant Patients diagnosed with Grade A or Grade B mild reflux oesophagitis (according to the Los Angels classification) through endoscopic test Patients who complained about "heartburn symptom" within one week prior to the enrollment Exclusion Criteria: Patients whose "heartburn symptom" has been disappeared (not been observed at all) during the observation period (Check before official enrollment) Patients in ill compliance with dosing the investigational product for the observation period (Not more than 75%, check from the patient dairy before official enrollment) Patients the investigator/sub-investigator assessed difficult to complete the patient diary during the treatment period because the patient diary for the observation period has too many deficiencies. (Check before official enrollment) Patients with complication of gastric/duodenal ulcer (scarring acceptable) Patients with complication of Barrett lining over the site exceeding 3 cm of esophageal distal portion Patients who have received the normal dose of H2 receptor antagonist or proton pump inhibitor (PPI) for 8 weeks in vain Patients whose Helicobacter pylori was successfully eradicated within 24 weeks Patients with medical history of upper gastrointestinal tract excision Patients with complication of angina pectoris Patients who have received treatment of any other investigational product within 12 weeks Patients who showed any of the following values at the laboratory tests before official enrollment: Hemoglobin: < 9.5 g/dL, WBC: < 3,000/mm^3, Thrombocytes: < 75,000/mm^3, AST and ALT : ≥ 100 IU/L, Creatinine: ≥ 1.5 mg/dL These should be assessed using the current test values from the blood drawn within 4 weeks prior to official enrollment. Patients with complication of serious cardiac disorder (Grade 3 or above under PAB/SD Notification No. 80) For example, patients with triplet or more ventricular premature contractions (multi-sources) or using a pacemaker Patients with medical history of serious hypersensitivity to drugs (Grade 3 or above under PAB/SD Notification No. 80) Patients who receive treatment of cancer Women of confirmed or potential pregnancy, those who wish to become pregnant, and breast feeding women Patients having any other condition that, in the opinion of the investigator/sub-investigator disqualifies them for the trial