Prokinetics to alter the position of the gastric acid pocket in Gastro Esophageal Reflux Disease

INTERVENTION: Administration of azitromycin. CONDITION: ; Gastroesophageal reflux Disease (GERD), Heartburn ; ; PRIMARY OUTCOME: The rate of acid reflux episodes. SECONDARY OUTCOME: 1. The rate of acid versus non acid reflux events; ; ; 2. The position of the acid pocket, relative to the lower esophageal sphincter and crural diaphragm; ; ; 3. The rate of TLESRs; ; ; 4. Gastric emptying. ; INCLUSION CRITERIA: GERD patients with a hiatal hernia: 1. 18‐65 years; 2. Esophagitis and/or pH‐metry with an acid exposure of > 4,5%; 3. Hiatal hernia as seen on endoscopy or barium swallow of > 3 cm. GERD patients without a hiatal hernia: 1. 18‐65 years; 2. Esophagitis and/or pH‐metry with an acid exposure of > 4,5%; 3. No hiatal hernia or a hiatal hernia < 2 cm as seen on endoscopy or barium swallow.