Achalasia is a condition characterized by swallowing difficulties, regurgitation and sometimes chest pain. It occurs when the smooth muscle layer of the esophagus doesn’t move food down the esophagus to the stomach the way it is supposed to, and the bottom of the esophagus (known as the lower esophageal sphincter) fails to relax and open. Occurring in about one in every 100,000 people per year, achalasia has no known underlying cause, though it is associated with the failure or loss of certain neurons in the wall of the esophagus. Traditional treatments for achalasia include the injection of botulinum toxin (Botox), stretching the lower esophageal sphincter with a balloon, and surgery, all of which reduce the pressure within the lower esophageal sphincter to allow easier passage of food.