A wide variety of therapies have been suggested for patients with painful esophageal motility disorders. In a prospective, double-blind, cross-over clinical trial, we evaluated the effectiveness of mercury bougienage ("placebo," 24 F; "therapeutic," 54 F) in eight symptomatic patients with the nutcracker esophagus (NE). There were no significant differences between the placebo or therapeutic dilators in relation to chest pain, dysphagia, lower esophageal sphincter pressure, or amplitude. Chest pain scores after completion of this trial were significantly lower than baseline scores, irrespective of the sequence of dilators used. No subjective or objective improvement could be demonstrated when "therapeutic bougienage" was compared with "placebo bougienage" in patients with the NE. The improvement in symptoms at the completion of the study may result from the close physician-patient interaction, suggesting that this may be more important than the actual size of the bougie.