Review article: diagnosis and investigation of gastro-oesophageal reflux disease in Japanese patients

Gastro-oesophageal reflux disease (GERD) encompasses a wide range of disorders defined by either reflux-related symptoms or by complications of gastro-oesophageal reflux. The most characteristic GERD symptoms are heartburn and acid regurgitation. Patients with these symptoms are in most cases easily identifiable and diagnosis is made on the basis of symptoms alone. For patients with a decreased frequency of heartburn, diagnosis is more difficult, and endoscopy is the single best test for diagnosis of GERD. A major difference between the West and Asia is the frequency of endoscopic investigation. In Japan, the earlier high prevalence of stomach cancers resulted in the increased use of endoscopy as an investigational tool for dyspeptic symptoms and today endoscopy continues to be widely available as a diagnostic tool. However, the overall sensitivity of endoscopy for the diagnosis of GERD is less than 50% since not all patients will have oesophagitis at the time of endoscopy. Ambulatory pH monitoring is therefore a frequently used diagnostic tool as it allows correlation between reflux events and symptoms, and is especially useful in patients with atypical or extraoesophageal symptoms. Oesophageal manometry is also an excellent test to evaluate oesophageal function and to measure sphincter pressure and while it may not provide an unequivocal diagnosis of GERD it is a useful tool with which to evaluate oesophageal function.