Objectives of the trial To assess the efficacy of omeprazole in combination with domperidone regarding change of incidence and severity of clinical symptoms of GERD during 8 weeks of treatment To compare the efficacy of omeprazole in combination with domperidone regarding change of incidence and severity of clinical symptoms of GERD during 8 weeks of treatment To assess the efficacy of omeprazole in combination with domperidone regarding change of incidence and severity of endoscopic symptoms of GERD during 8 weeks of treatment To compare the efficacy of omeprazole in combination with domperidone regarding change of incidence and severity of endoscopic symptoms of GERD during 8 weeks of treatment To determine the efficiency and advantages of one GERD therapy considering efficacy, safety, and individual variance of patients' reactions