A concomitant treatment by CO2-releasing suppositories improves the results of anorectal biofeedback training in patients with dyschezia: results of a randomized, double-blind, placebo-controlled trial.

Background: Dyschezia is a defecatory disorder that places a heavy burden on a patient's quality of life. Biofeedback is the recommended treatment in most cases.

Objective: The objective of our study was to test whether a CO2-releasing suppository for patients with dyschezia could be effective in improving biofeedback training results.

Design: A randomized, double-blind, multicenter, placebo-controlled study was conducted in patients (18-75 years of age) with dyschezia defined according to the modified Rome III criteria. Patients were randomly assigned to either a CO2-releasing suppository or placebo suppository once per day for 21 days.

Settings: This was a multicenter trial.

Patients: A total of 122 patients were randomly assigned (62 intervention group and 60 placebo group).

Main Outcome Measures: The primary end point was the change from day 0 to day 21 in intensity of symptoms on the basis of a self-assessed dyschezia using a visual analog scale (range, 0-100). Analyses were performed using intention-to-treat principles.

Results: A greater reduction from baseline to day 21 in symptom visual analog scale score was observed in the intervention group (-41.3 mm) than in the control group (-22.3 mm). Some secondary efficacy parameters improved more in the intervention group, including the percentage of patients who improved ≥50%, symptom intensity over 21 days, stool stains on underwear or pads, and need to practice manual maneuvers to facilitate defecation at day 21. At day 21, rectal sensitivity in the intervention group (31.4 mL) was lower than in the control group (39.1 mL).

Limitations: There was a lower number of patients recruited than planned by the protocol. The sponsor stopped the trial before the inclusion of 306 participants, with no intermediate analysis. In addition, the main analysis conducted on the full analysis set population could have led to a statistical bias.

Conclusions: The results of this multicenter trial demonstrate the added benefits of a CO2-releasing suppository in patients with dyschezia who were treated by anorectal biofeedback training.