Lower Esophageal Sphincter (LES)

Lower Esophageal Sphincter (LES) What is the role of The lower esophageal sphincter (LES)? The lower esophageal sphincter (LES) is a ring of muscle that forms a valve at the lower end of the esophagus where it joins the stomach. The LES stays closed except during swallowing, when it allows food to pass from the...