A pilot randomised controlled trial comparing a stool softener versus osmotic laxatives following obstetric anal...

Obstetric Anal Sphincter Injuries (OASIs) are associated with significant maternal morbidity, specifically anal incontinence. There is a lack of robust evidence guiding postoperative management of OASI creating variation amongst types of laxatives used. This pilot study compares a stool softener and an osmotic laxative to assess ease of evacuation, defecation outcomes, continence status (anal incontinence), wound dehiscence and the impact of laxatives on quality of life in women following OASI repair in the postpartum period.

Women who birthed and sustained an OASIs were allocated to one of two treatment groups: a 'CF group' (docusate© 200 mg daily) or 'LF group' (lactulose ©15mls BD (twice daily)). Bulking fibre (ispaghula©) was given to both groups (one sachet twice daily) for 14 days. Pain on defecation, anal incontinence, wound breakdown, and quality of life (QoL) were assessed at 2, 6 and 12 weeks post birth.

Forty women with OASIs (67 %) were recruited and randomized to stool softener (n = 22) or osmotic laxative (n = 18) group after repair. No difference was seen in defecation outcomes, AI, wound breakdown or QoL. AI was reported in the first two weeks in 10 (25 %) women increasing to 18 (45 %) at 12 weeks. Flatus and fecal urgency were predominant symptoms. Other factors including fissures and haemorrhoids were identified in 12 (30 %) women contributing to pain and AI.

There was no relationship between laxative management and wound breakdown, anal incontinence and quality of life between groups. The pilot trial design is feasible to replicate as a larger study with minor adjustments to collection tools. Further research is also required to determine the relationship between ethnicity, diet, and laxatives on gut function.