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A pilot study to compare stool softeners versus osmotic laxatives following obstetric anal sphincter injury examining defecation outcomes, wound dehicence and risk of anal incontinence

A pilot study to compare stool softeners versus osmotic laxatives following obstetric anal sphincter injury examining defecation outcomes, wound dehicence and risk of anal incontinence

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ANZCTR
Registry ID
ACTRN12622001154796
Acronym
OASIS
Enrollment
40
Registered
2022-08-23
Start date
2023-02-10
Completion date
2023-12-07
Last updated
2025-09-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Following childbirth tears to the perineum (area between the vaginal and bowel) and vagina are common occurring in 80 to 90% of women. Tears to the anus (bottom muscle) known as 3rd or 4th degree tears and occur in 3.5% of women giving birth in Australia. To promote healing of these tears, medications are given to soften the stool (poo). Currently all women following childbirth who have sustained a tear to the bowel muscles (3rd or 4th degree tear) would have laxatives ordered. Several types of medications known as laxatives are prescribed however we do not know which one is the best. If you choose to be involved in the research, you will be allocated one of two laxatives that are prescribed for women following birth. The research team contact you and ask you about how easy it was to open your bowels (Poo), if you had any bowel incontinence (accidental loss of poo, gas or need to rush to the toilet for a Poo) or any concerns with healing of the wound (stitches). Information from this research will help guide development of a larger trial in the future. The research project aims to see how several types of laxatives affect 1. How easy or hard it was to use your bowels (Poo) after birth and until 3 months following the birth of your baby. 2. If you have accidental leakage of (Poo), called anal incontinence following birth until 3 months post birth. 3. Any concerns about healing of the stitches (3rd and 4th degree tear) following birth until 3 months post birth. ? The Continence Nursing team routinely provide follow up care to women following 3rd and 4th degree tears. As part of the research, and on discharge from hospital, you will only be required to provide verbal feedback to questions on three occasions, about how easy or difficult it was to use your bowels (do a poo) if you have accidental loss of poo (anal incontinence) and how the

Interventions

osmotic laxatives (lactulose) 15mg twice daily oral liquid. Medication for 2 weeks, commencing day 1 post birth on postnatal ward and continue for 2 weeks post discharge to home. Medication compliance assessed in hospital by medication chart completion and on discharged check by continence team 2 week phone call. Bulking fibre (Ipsaghula) is routinely given to postnatal women and will continue to be prescribed at one sachet twice daily for 2 weeks. Each sachet obtains 3.5mg of ispaghula husks mi

osmotic laxatives (lactulose) 15mg twice daily oral liquid. Medication for 2 weeks, commencing day 1 post birth on postnatal ward and continue for 2 weeks post discharge to home. Medication compliance assessed in hospital by medication chart completion and on discharged check by continence team 2 week phone call. Bulking fibre (Ipsaghula) is routinely given to postnatal women and will continue to be prescribed at one sachet twice daily for 2 weeks. Each sachet obtains 3.5mg of ispaghula husks mixed in one glass of water (150ml) and taken orally twice daily. Medication commenced and assessed for compliance as above for 2 week timeframe.

Sponsors

Dr Elizabeth Murphy
Lead SponsorIndividual

Study design

Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)

Eligibility

Sex/Gender
All
Age
16 Years to No maximum
Healthy volunteers
No

Inclusion criteria

All women sustaining an obstetric anal sphincter injury at the study site who can provide informed consent

Exclusion criteria

History of anal incontinence No obstetric anal sphincter injury History of chronic constipation History of colorectal disease such as inflammatory bowel disease or colorectal malignancy Allergy to study medication

Outcome results

None listed

Source: ANZCTR · Data processed: Feb 4, 2026