Rectal motility studies in faecally incontinent geriatric patients.

Rectal motility was assessed in three groups of geriatric patients (faecally incontinent, continent faecally impacted and control patients) to determine whether 'uninhibited' rectal contractions are a cause of faecal incontinence. The incidence of rectal contractions in response to rectal distension did not differ between the three study groups. Two-thirds of the incontinent patients were unable to retain a condom distended with water (soft-stool model) during a proctometrogram. Involuntary expulsion of this device was correlated with the presence of rectal contractions and low anal resting pressure. Involuntary expulsion of an airfilled balloon (firm-stool model) from the rectum occurred less frequently and was correlated with low resting pressure but not with rectal contractions. The contribution of 'uninhibited' rectal contractions to faecal incontinence is insignificant except for a minor role in the expulsion of liquid stool.