Placebo response to sham electroacupuncture in patients with chronic functional constipation: A secondary analysis.

Electroacupuncture did not demonstrate a large placebo response in functional constipation treatment. The number of CSBMs at baseline may be a moderator of the placebo response to sham electroacupuncture. Thus, superficial needling sham acupuncture may be considered an ideal sham control for clinical trials of chronic constipation.