Stimulation of the incompetent lower esophageal sphincter

The primary function of the lower esophageal sphincter (LES) is to prevent the reflux of gastric contents into the esophagus. We have studied the effect of hormonal and pharmacologic stimuli on LES pressure in patients with symptomatic gastroesophageal reflux due to LES incompetence. Gastric alkalinization, subcutaneous pentagastrin, intravenous edrophonium, and subcutaneous bethanecol each resulted in marked increases in LES pressure. In all studies, pressure rose to a level occurring in normal subjects. Subsequently, the patients were given 25 mg bethanecol orally and pressure monitored for 2 hours. The LES pressure increased from a mean basal pressure of 5.6±0.8 mmHg to a peak of 16.9±2.8 mmHg at 50 minutes. Pressure remained elevated for the full 2-hour study period. Both subcutaneous and oral bethanecol successfully increased LES pressure in all patients with symptomatic reflux to the level of resting pressure seen in normal subjects. These studies suggest a potential role for cholinergic agents in the therapy of symptomatic gastroesophageal reflux.The opinions expressed herein are those of the authors and cannot be construed as reflecting the views of the Navy Department or of the Naval Service at large.Presented at the 53 rd Annual Session of the American College of Physicians, April 19, 1972, Atlantic City, New Jersey.