A proportion of patients with faecal incontinence experience debilitating urgency of defaecation and urge incontinence. This study prospectively assessed 56 faecally incontinent patients by means of standard interview, physical examination and anorectal physiology. Patients with urge incontinence, when compared with those without urge incontinence, were symptomatically worse, had had more vaginal deliveries and had more bowel actions each day. Physiological tests included anal manometry, anal electrosensitivity, pudendal nerve terminal motor latency and a standard proctometrogram. The only physiological differences between the groups were a reduction in voluntary squeeze pressure (median (interquartile range (i.q.r.)) 43 (26-67) versus 67 (45-122) mmHg, P = 0.01) and a smaller percentage change in pressure-volume, an integral of sphincter length and squeeze (median (i.q.r.) 43.5 (0-289) versus 247 (71-455), P = 0.02), in those with urgency. The authors conclude that urge incontinence is associated with impairment of the striated musculature of the anal sphincter complex.