Diagnosis of gastroesophageal reflux disease.

The diagnosis of gastroesophageal reflux disease (GERD) is based primarily on the patient's symptoms and their evaluation. The most common symptoms, heartburn and acid regurgitation, when occurring daily, have a 60% predictive value for the diagnosis. The presence of esophagitis is established best by endoscopy, whereas the radiological examination is relatively insensitive and normal radiological findings never rule out esophagitis. Tests to evaluate the sensitivity of the esophageal mucosa to an acidic pH or to evaluate the strength of the lower esophageal sphincter as an antireflux barrier are valuable indicators of GERD, but only long-term, preferably 24-h, ambulatory pH measurements can provide information on incidence and duration of reflux and its relationships to the patient's symptoms and activities under physiological conditions. However, for practical and economical reasons, 24-h pH measurement should be applied only when symptoms are atypical and endoscopy was unrevealing.