Treatment of functional constipation with the Yun-chang capsule: a double-blind, randomized, placebo-controlled, dose-escalation trial.

Background And Aim: Functional constipation is a common functional bowel disorder for which there is no reliable medical treatment. This study was designed to determine the therapeutic efficacy and safety of the Yun-chang capsule, a Chinese herbal formula, in the treatment of patients with functional constipation.

Methods: In our multi-center, prospective, double-blind, randomized, placebo-controlled, dose-escalation trial, patients with functional constipation received 70 mg of Yun-chang capsule plus 35 mg placebo (group A), 105 mg of Yun-chang capsule (group B), or 105 mg placebo (group C), three times daily for 2 weeks. The primary end-points were the changes in main symptom score and cumulative symptom score 2 weeks after the treatment. The secondary end-points were adverse events.

Results: A total of 140 patients were recruited and 132 met the inclusion criteria; 44 patients constituted each of the three treatment groups. Compared with patients in group C, patients in groups A and B had significant improvement in the main symptom score, cumulative symptom score, the change from baseline of the main symptom score, and the change from baseline of the cumulative symptom score at week 1 and week 2. The scores showed slight superiority of group B over group A at week 1 and week 2, although these differences were not statistically significant. There were no differences in adverse events.

Conclusions: The Yun-chang capsule is efficacious and safe for the treatment of patients with functional constipation. Larger and longer-term trials are required to fully assess the benefits and safety of this treatment for functional constipation.