Anterior sphincter repair for faecal incontinence related to obstetric
trauma was performed in 55 patients: 32 with incontinence after deliv
ery and 23 with late onset. Anal endosonography and physiological test
s were performed before and after surgery. After a median of 15 (range
6-36) months, 42 patients had improved, 11 had not improved and two w
ere awaiting colostomy closure. The postoperative squeeze pressure was
increased (by 20 versus 5 cmH(2)O, P=0.05) and the external sphincter
was more frequently intact (32 of 35 versus five of 11, P=0.003) in t
hose with a good outcome. Patients with an intact external sphincter h
ad higher postoperative squeeze pressures (50 versus 20 cmH(2)O, P=0.0
04). Patients with late-onset incontinence were older than those who d
eveloped incontinence soon after delivery (median 59 versus 32 years,
P<0.001) and had longer pudendal nerve terminal motor latencies (2.3 v
ersus 2.1 ms, P=0.03). Failure of repair is related to persistent exte
rnal sphincter defects. Late-onset incontinence, even with a prolonged
pudendal nerve terminal motor latency, does not preclude a good outco
me.