The lower esophageal sphincter, or LES, is responsible for preventing the backflow of stomach contents and for allowing food to easily pass through the esophagus while swallowing. According to The
Mayo Clinic, the lower esophageal sphincter can occasionally become weak due to a chronic digestive disease called gastroesophageal reflux disease. Gastroesophageal reflux disease, or GERD, can be a major burden that causes heartburn, dysphagia, sore throat and acid reflux.