['Acid plays a significant role in the development of gastroesophageal reflux symptoms, such as heartburn and regurgitation. It is generally assumed that acid suppressive therapy improves or eliminates symptoms by normalizing intraesophageal pH.', "The aim of this article was to assess the efficacy of proton-pump inhibitors (PPIs) in normalizing intraesophageal and intragastric pH in patients with GERD without Barrett's esophagus (BE) rendered symptom free by therapy.", 'Patients were evaluated by dual-sensor 24-h pH monitoring while receiving PPI therapy for complete control of GERD symptoms. Analyses of intraesophageal and intragastric pH profiles were then made.', 'Fifty patients, 39 men and 11 women, with GERD, without BE, were studied. All tolerated PPIs well and were asymptomatic at the time of the study. Fifty percent of patients had abnormal intraesophageal pH profiles despite adequate symptom control on PPIs, which was associated with significant breakthrough of intraesophageal acid control in both the upright and supine positions. Low intragastric pH correlated highly with intraesophageal acid reflux only in patients with persistent abnormal esophageal acid exposure (p= 0.001).'] Does complete elimination of reflux symptoms guarantee normalization of intraesophageal and intragastric pH in patients with gastroesophageal reflux disease ( GERD )?