Achalasia is a disorder of the esophagus (the passageway for food from the mouth to the stomach) that makes it difficult for food and fluid to pass into the stomach. Normally, the esophagus is empty between swallows. When a person swallows, muscle contractions sweep down the esophagus, the esophageal sphincter (the opening at the lower end of the esophagus) opens, and food or fluid passes into the stomach. People with achalasia have difficulty swallowing because the wave of muscle contractions that sweep food and fluid down the esophagus does not occur. In turn, the esophageal sphincter does not open properly, so food and fluid cannot pass into the stomach. With Achalasia, food and fluid remain trapped in the esophagus causing discomfort and other symptoms. The esophagus usually becomes wider than normal.
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