Regurgitation of the gastric contents into the esophagus is common and often unnoticed. When symptoms such as heartburn, a sour or bitter taste in the mouth, or even chest pain mimicking angina pectoris or myocardial ischemia prompt a patient to seek help, the factor or factors responsible for reflux must be sought. The possible underlying causes are numerous, as Dr Bachman points out in this discussion of the pathophysiology, diagnosis, and treatment of gastroesophageal reflux. The desired end point of management was well stated by Seneca over 2,000 years ago as "a good-humored stomach."