Achalasia is a rare disorder that makes it difficult for food and liquid to pass into your stomach. Achalasia occurs when nerves in the tube connecting your mouth and stomach (esophagus) become damaged. As a result, the esophagus loses the ability to squeeze food down, and the muscular valve between the esophagus and stomach (lower esophageal sphincter) doesn’t fully relax — making it difficult for food to pass into your stomach.
There’s no cure for achalasia. But symptoms can usually be managed with minimally invasive therapy or surgery (source)