Temporary sacral nerve stimulation in patients with fecal incontinence owing to rectal hyposensitivity: a prospective, double-blind study.

BACKGROUND: Rectal hyposensitivity (RH) can lead to fecal incontinence (FI). Sacral nerve stimulation (SNS) is known to modulate rectal sensation, but no data about affecting FI owing to RH are available. This prospective study aimed to assess the therapeutic effect of temporary SNS on patients with FI owing to RH.

METHODS: Twenty-four patients with FI owing to RH had temporary SNS (4 weeks on followed by 1 week off). Before SNS (baseline), after 4 weeks of stimulation (on), and at the end of the off week we recorded first constant sensation (FCS), defecatory desire volume (DDV), maximum tolerated volume (MTV), anal pressures, bowel diaries, Wexner incontinence score, and FI quality-of-life score (FIQOL).

RESULTS: There were significant decreases in DDV and MTV during the on-treatment period (P < .0001); this decrease was not significant during the off period. FCS was not significantly affected by SNS. FI episodes significantly improved during the on period in 22 patients (from 5.3 to 1.1 per week; P < .0001) and mean Wexner incontinence score improved from 13.3 to 1.7 (P < .0001). Anal pressures (resting and squeeze) significantly increased during the on period but not during the off period. There was significant improvement in FIQOL during the on period only.

CONCLUSION: SNS can be effective in restoring continence and improving QOL in patients with FI owing to RH. Improved continence might be related to improvement of rectal sensation and/or increased anal pressure. The washout effect of SNS on the continence score, DDV, and MTV after cessation of stimulation needs to be explained.