Symptomatic, or nonerosive, gastroesophageal reflux disease (GERD) is the most common presentation of GERD. Patients with symptomatic GERD more frequently are younger, female, weigh less, and are less likely to have a hiatal hernia compared with patients who have erosive GERD. Physiologically, these patients demonstrate minimal esophageal motor abnormalities. However, despite a common clinical presentation and similar endoscopic findings, symptomatic GERD is comprised of a heterogeneous group of patients. There are several identifiable subgroups differentiated by the underlying mechanisms causing their heartburn symptoms, distinctions that may explain the relatively low symptom response rate to potent antireflux treatment observed among these patients as compared with those with erosive esophagitis.