Effects of Tibial Nerve Electrostimulation in Patients With Fecal Incontinence: A Systematic Review.

Most of the 17 studies had no control group. Only two were randomised trials, so the improvements reported could reflect placebo, the extra attention of weekly appointments, or symptoms settling on their own rather than the stimulation itself. The review could not pool the data. The studies differed in design, participants, how success was defined, which questionnaires were used and what stimulation settings were applied, so the overall size of any effect is unknown. Risk of bias was often high. The non-randomised studies scored between 3 and 8 out of 9 on the Newcastle-Ottawa scale, and even the CONFIDeNT randomised trial was judged to have some concerns, mainly about selection of reported results. Sphincter integrity was not assessed in a standard way, so the review could not work out which patients are most likely to respond. Participants were mostly women in their fifties and sixties who had already failed conservative treatment, so the findings may not apply to men, younger people or those seen earlier in the treatment pathway. One included study combined tibial nerve stimulation with anorectal biofeedback, so the contribution of the stimulation on its own cannot be separated.

The authors declare no conflicts of interest and report no funding.

Do not read 'all 17 studies reported improvement' as proof that tibial nerve stimulation works for fecal incontinence. Most of those studies had no control group, and the sham-controlled trials found no significant difference between active stimulation and sham, so much of the improvement may be placebo or natural recovery rather than the treatment.