Enrolled patients will undergo collection of salivary and esophageal secretions. Subsequently, all patients will receive rabeprazole (20mg QD) for 8 weeks and will be re-endoscoped to confirm complete healing of reflux esophagitis. In patients with completely healed reflux esophagitis the second collection of salivary and esophageal secretion will be implemented. In both secretions, adequately coded for the laboratory Research Fellow (blinded in terms of which sample is collected before and which after treatment with rabeprazole) the content of mucin will be measured using commercially available assay and its secretion expressed in units per minute of collection time.