Update in the diagnosis of gastroesophageal reflux disease.

Clinical manifestations of gastroesophageal reflux disease (GERD) include heartburn, regurgitation, dysphagia, chest pain, cough and other extraesophageal symptoms. GERD is known to cause erosive esophagitis, Barrett esophagus and has been linked to the development of adenocarcinoma of the esophagus. Currently upper gastrointestinal endoscopy is the main clinical tool for visualizing esophageal lesions. Since the majority of GERD patients do not have endoscopic visible lesions other methods are required to document the abnormal acid exposure in the distal esophagus. For many clinicians ambulatory esophageal pH monitoring is the gold standard in diagnosing GERD since it quantifies distal esophageal acid exposure and allows the evaluation of the relationship between symptoms and acid reflux. The availability of highly selective gastric acid suppressive therapy led to the introduction of short trials of proton pump inhibitors (PPI) to diagnose GERD. PPI trials are often used as a first line diagnostic tool in clinical practice and in particular in the primary care settings. This development has a major influence in the type of patients referred to gastrointestinal specialists, the current trend being that gastroenterologists are asked to evaluate an increasing number of patients with persistent GERD symptoms while on PPI therapy. In these patients the question is whether the persistent symptoms are or not associated with reflux (acid or non-acid). In the recent years combined multichannel intraluminal impedance and pH (MII-pH) monitoring has become a clinical tool that permits the clarification of the mechanisms underlying the persistent symptoms on acid suppressive therapy.