Return of peristalsis in achalasia after pneumatic dilatation.

Distally progressive contraction waves were demonstrated in seven of 34 (20%) patients with achalasia, successfully treated with pneumatic dilatation. There was no correlation between the appearance of such waves and clinical status, the decrease in lower esophageal sphincter resting pressure, or in the radiographically measured diameter of their esophagus. Return of these waves cannot be adequately explained by the "common cavity phenomenon."