Interferential therapy for chronic constipation in adults: The CON-COUR randomizedcontrolled trial.

Background: Chronic constipation (CC) is a frequent condition, and the first-line treatment includes dietary rules, the use of laxatives, and biofeedback for evacuation disorders. However, almost half of the patients are dissatisfied with their current treatment. We report the first double-blind randomized multicenter trial assessing the effectiveness of transabdominal electrical stimulation by interferential therapy (IFT) in the treatment of CC in adults.

Methods: A prospective, multicenter, randomized, double-blind, sham-controlled, parallel-group, phase 3 trial was conducted at 7 centers in France. The primary endpoint was 8-week efficacy as defined by the number of complete spontaneous bowel movements during the last 4 weeks of the 8-week stimulation period. Secondary endpoints included the evaluation of the effects of IFT on symptoms (Patient Assessment of Constipation Symptoms questionnair (PAC-SYM)), quality of life (QOL) (Patient Assessment of Constipation Quality of Life), Colonic transit time (CTT), anorectal manometry, and patient satisfaction.

Results: The proportion of 8-week responders was not significantly different between the two groups (73.2% in the IFT group vs. 67.1% in the sham group). After 8 weeks of stimulation, the mean overall PAC-SYM score and the mean reduction in the overall PAC-SYM score were significantly greater in the IFT group than in the sham group. No differences were observed concerning CTT, anorectal manometry, or patient satisfaction.

Conclusions: Although the primary endpoint was not reached, IFT can significantly alleviate the symptoms and improve the QOL of CC patients. It can be assumed that new treatments require different modes of evaluation and that the assessment of patient-reported outcomes may become a priority among therapeutic targets of CC. Trial registration number NCT02381665.