Deranged gastric motility and delayed gastric emptying are commonly implicated in the pathophysiology of gastroesophageal reflux disease. We measured gastric electrical activity and gastric emptying time of a solid-liquid meal by electrogastrography and antral ultrasound, respectively, in 42 patients with gastroesophageal reflux disease (age 7.4 +/- 1.6 yr). Based on endoscopy and histology of the esophageal mucosa, reflux disease was moderate in 20 patients and severe in 22. Electrogastrography was measured by placing two Ag-AgCl electrodes on the epigastric skin, signals were digitized and fed into a personal computer, and data were obtained by running spectrum analysis. The electrogastrographic variables calculated were: 1) percent of electrical dysrhythmias and normal electrical rhythm (bradygastria or 0.5-2.0 cycles/min, tachygastria or 4.0-9.0 cycles/min; normal rhythm is 2.0-4.0 cycles/min); 2) fed:fasting ratio of dominant electrogastrographic power; 3) fed:fasting ratio of the dominant frequency instability coefficient. Gastric emptying time and electrical activity results were compared with those measured in 15 controls (7.1 +/- 1.7 yr). Dysrhythmic episodes were more common in both groups of patients than in controls (p < 0.01); furthermore, gastric emptying time was significantly more delayed in patients than in controls (p < 0.01). Children with severe gastroesophageal reflux were distinguished from those with moderate disease for post-feeding gastric electrical abnormalities consisting of reduced electrogastrographic dominant power and increased frequency variability (p < 0.01), as well as for a more prolonged gastric emptying time (p < 0.05). Prevalence of both normal electrical rhythm and dysrhythmias did not discriminate the two groups of patients. In patients and in controls, a significant inverse correlation between fed electrogastrographic power and gastric emptying time was found (r -0.88, p < 0.01). Fed gastric electrical abnormalities consisting of reduced dominant power and increased variability of the electrical dominant frequency are detected in patients with severe gastroesophageal reflux disease and are associated with delayed gastric emptying. Gastric electrical dysrhythmias may be included among the pathogenetic components of gastroesophageal reflux disease.