Physiology of the Antireflux Barrier and Diagnostic Tests of Foregut Function

Abstract

The major causes of increased esophageal exposure to gastric juice are mechanical deficiencies of the lower esophageal sphincter, ineffective esophageal clearance, and abnormalities of the gastric reservoir. The various manifestations of these reflux components are discussed, and diagnoses of structural and functional foregut diseases are reviewed. Endoscopy and barium radiography can provide diagnostic information about structural disease, but esophageal function studies must be conducted to examine functional disease. Indications for stationary esophageal manometry are reviewed, and techniques are described. Twenty-four hour pH monitoring also is reviewed. Additional tests for investigating esophageal disease include dual esophageal pH monitoring, ambulatory esophageal manometry, and esophageal bile probe. Indications for gastric function studies are considered, and the analyses of gastric emptying and gastric acid are reviewed. New techniques that may improve diagnostic capabilities include the use of a gastric bile probe, the study of antroduodenal motility, and the scintigraphic imaging of bile reflux.