Measurement of Gastric Secretion by MRI Under Inhibition by ProtonPump Inhibitors in Healthy Subjects & in GERD Patients

Inclusion criteria: - Healthy volunteers must have less than one episode of reflux or dyspeptic symptoms per month of no more than mild severity in the last 3 months \- Reflux patients (GERD) must have chronic symptoms (\>8 weeks) suggestive for GERD (definition and questionnaire see Appendix page 30). In addition, the initial screening manometry must show no severe esophageal dysmotility (e.g. spasm, achalasia). If in addition a pH-study has been performed the acid exposure must be \> 4.2% / 24h. Exclusion criteria: - Age under 18 or above 65 * Pathologic underweight or overweight (BMI \< 18 or \> 30 kg/m2) * Previous history of gastrointestinal disease or surgery (excludes appendectomy, cholecystectomy, hernia repair and anorectal disorders) * Previous cardiorespiratory (excludes arterial hypertension), hematologic, renal, atopic, alimentary or psychiatric disease, diabetes, drug or alcohol abuse * Patient unable to stop medication that alters gut function for 72 hours prior to the study, including anticholinergics, prokinetics, proton-pump inhibitors, non-steroidal anti-inflammatory drugs * Positive Helicobacter pylori status on 13C-Urea breath test * Presence of metallic implants, devices or metallic foreign bodies * Pregnancy and lactation (female patients of child bearing age will receive a pregnancy test prior to study) * Female volunteers without adequate contraception for the duration of the study * Involvement in any other clinical trial during the course of this trial, nor within a period of 30 days prior to its beginning or 30 days after its completion