A technique for the dynamic assessment of anal sphincter function.

A technique which renders continuous measurement of the cross-sectional area and pressure of the anal canal possible during distension and contraction of the anal sphincter has been developed. Electromyography of the external sphincter is measured simultaneously. With this technique a more detailed assessment of anal sphincter function is possible, including the opening and closing pressures of the sphincter at rest, anal compliance, anal hysteresis and the maximal closing pressure during squeeze. The results of in vitro measurements, measurements on 16 healthy subjects and 6 patients with faecal incontinence are presented.