Achalasia in the elderly. Effects of aging on clinical presentation and outcome. Clinical and manometric data from 13 elderly subjects with idiopathic achalasia (mean age 79 +/- 2 years) were compared with findings from younger subjects with the same disease (n = 79) to see if aging altered the presentation and outcome of this motor disorder. Fewer elderly subjects complained of chest pain (27% vs 53%), and the pain was significantly less severe (P less than 0.01). Other presenting features (including sex, duration of symptoms, and presence and severity of dysphagia) did not differ between the groups. Across all patients, age weakly and inversely correlated with residual postdeglutitive lower esophageal sphincter; (LES) pressure (R = -0.34), and residual pressure was significantly lower in the older subjects (8.0 +/- 1.3 mm Hg vs. 11.9 +/- 0.8 mm Hg; P = 0.02). No differences in basal LES pressure or esophageal-body contraction amplitudes were present between the groups. Initial success with pneumatic dilation was similar in the two subject groups, but the number of older subjects available for analysis was too small to draw strong conclusions. These results indicate that aging decreases the elevation of LES residual pressure that occurs with achalasia. As elderly achalasia patients also present with less chest pain, the findings may be interrelated. 