Introduction Traumatic vaginal delivery is closely correlated with attenuation of anorectal structure and function, and hence symptoms of faecal urgency (FU) and incontinence (FI). We aim to describe the immediate clinical and physiological effect of overt perineal trauma in patients within 6 months of injury.

Methods One hundred consecutive postpartum (3–6 months) patients who sustained an obstetric tear at delivery were studied over a 13 month period. Mean age was 33 years (range 22–51 years old), 75 women were older than 30 years. All patients underwent anorectal physiology (ARP) and endoanal ultrasound (EAUS) as per Unit protocol.

Results Cohort: 84 of these obstetric tears were first vaginal delivery; of 16 who were multiparous, 11 had also sustained tears in their first delivery. Ten women sustained a 2^nd degree tear, 84 a 3^rd degree tear (3 a=45; 3 b=33; 3 c=6) and 6 women a 4^th degree tear. Instrumentation was necessary in 55 of cases (43 forceps, 11 ventouse and 1 combination). Regarding other risk factors, birth weight was over 4 kg in 26 and 32 required an episiotomy. The table shows symptom burden at median 4 months; 60 patients were symptomatic, presenting with more than one troublesome symptom.

Investigation: ARP demonstrated 17 with reduced resting sphincter pressure, 43 reduced voluntary squeeze and 27 inadequate endurance squeeze. Only 33 women had entirely normal manometry. Rectal hypersensitivity defined as two reduced thresholds to rectal mechanical distension was found in 11 patients. Similarly, abnormal anal and rectal electrosensory thresholds were seen in 20 and 5 women respectively. There was a significant correlation between those patients who had 3^rd degree tears and hypersensitivity to maximum balloon distension (p = 0.007) and reduced anal sensitivity (p = 0.005). Immediate post-partum repair is often unsuccessful, 56 women had a persistently disrupted or scarred external sphincter and 22 had a disrupted internal anal sphincter on EAUS.

Conclusion Maternal age over 30 and first delivery are disproportionately correlated to the likelihood of severe obstetric tears. The majority of women experience symptoms, of which the commonest are FU, FI and flatus incontinence. Sphincter disruption is often persistent despite attempted repair, and is associated with rectal hypersensitivity. Systematic investigation and clinical assessment is recommended to improve clinical management and offer counselling in regards to risks associated with future deliveries.

Disclosure of Interest None Declared