Modulation of the rectoanal inhibitory reflex (RAIR): qualitative and quantitative evaluation in multiple sclerosis.

Background: Rectoanal inhibitory reflex (RAIR) is a physiological modulated reflex involved in anorectal continence and defined by a relaxation of internal anal sphincter following rectal distension. Its existence depends on intramural autonomic ganglions and its modulation on the integrity of the autonomic nervous system (ANS).

Aims: The aim of this study was to analyse RAIR modulation in terms of amplitude and duration in multiple sclerosis (MS) patients.