Mary Anne Cooper MSc, MD, FRCPC, Department of Medicine, University of Toronto; Lecturer, Sunnybrook and Women’s Health Sciences Centre, Toronto, ON.
Gastroesophageal reflux disease (GERD), the abnormal reflux of gastric and duodenal contents into the esophagus, is common. Almost 50% of the North American population experience symptoms once a month and 10% have symptoms daily.1 Patients most commonly complain of pyrosis and regurgitation, but other symptoms such as dysphagia, chest pain and nausea are not rare.1 As well, respiratory tract symptoms such as cough, hoarseness and asthma may be attributable to GERD (Table 1).1,2
Acid reflux into the esophagus is a normal physiologic event. It occurs after meals when the lower esophageal sphincter (LES) tone is reduced. The LES opens, creating a common cavity with the stomach. Because stomach pressures are higher than esophageal pressures, gastric contents reflux into the esophagus. Formal measurement with 24-hour pH monitoring indicates that the pH of the esophagus should be < 4 for < 4% of the time. Factors that increase acid contact time with the esophagus promote GERD.