Pathophysiology of gastroesophageal reflux

The factors controlling competence of the gastroesophageal junction have been carefully analyzed over the last decade. Although the presence of an anatomic sphincter guarding the lower esophagus has not been confirmed in humans, a manometrically defined high-pressure zone is present in the lower esophagus. The magnitude of sphincter pressure correlates well with the incidence of pathologic gastroesophageal reflux. Another important determinant of cardial competence is the length of intra-abdominal esophagus. The interaction of length and pressure in maintaining competence is demonstrated by several clinical and experimental studies. Twenty percent of refluxors have normal components of cardial competence. Several physical factors, namely components of Laplace's law, may govern control of reflux especially after antireflux repairs. The occurrence of esophagitis as a complication of gastroesophageal reflux is determined by the ability of the esophageal body to rid itself of an acid load as well as by factors that delay gastric emptying.