Megaesophagus is a common disease characterized by dysphagia and abnormal dilatation of the organ. Although recognized for many years and the subject of numerous clinical and physiologic studies, the entity is not understood from the standpoint of etiology. It is indeed fortunate that specific therapy has been provided in a disease whose exact nature is unknown.
The terms cardiospasm, achalasia, and megaesophagus are used interchangeably. This is unfortunate and adds confusion to a subject already obscured by clinical mythology. The terms cardiospasm and achalasia imply lack of relaxation of the so-called cardiac sphincter. In other words, the circular muscle of the terminal esophagus, smooth and involuntary in action, fails to relax in coordination with the act of swallowing, and dysphagia results. This condition is extremely variable in degree and in itself does not constitute an irreversible problem. Every physician is familiar with the cardiospasm manifested by the emotional patient who