ANORECTAL PRESSURE-GRADIENT AND RECTAL COMPLIANCE IN FECAL INCONTINENCE

To study whether anorectal pressure gradients discriminated better tha n standard anal manometry between patients with fecal incontinence and subjects with normal anal function, anorectal pressure gradients were measured during rectal compliance measurements in 36 patients with fe cal incontinence and in 22 control subjects. Anal and rectal pressures were measured simultaneously during the rectal compliance measurement s. With standard anal manometry, 75% of patients with fecal incontinen ce had maximal resting pressure within the normal range, and 39% had m aximum squeeze pressure within the normal range. Anorectal pressure gr adients did not discriminate better between fecal incontinence and nor mal anal function, since, depending on the parameters used, 61%-100% o f the incontinent patients had anorectal pressure gradients within the normal range. Patients with fecal incontinence had lower rectal volum es than controls at constant defecation urge (median 138 mi and 181 mi , P<0.05) and at maximal tolerable volume (median 185 mi and 217 mi, P <0.05;). We conclude that measurements of anorectal pressure gradients offer no advantage over standard anal manometry when comparing patien ts with fecal incontinence to controls. Patients with fecal incontinen ce have a lower I ectal volume tolerability than control subjects with normal anal function.