Postpartum Faecal Incontinence

Postpartum faecal incontinence is involuntary loss of stool or flatus after childbirth. It is much more common after a third or fourth degree tear. It results from injury to the anal sphincter or its nerve supply, a missed sphincter tear, or breakdown of a repair. It matters because it causes shame and isolation, and early repair and pelvic floor care improve the outcome.

• Risk factors: third or fourth degree tear, forceps delivery, large baby, occiput posterior position, long second stage, first vaginal birth, episiotomy extension.
• Occult sphincter defects are found on ultrasound in up to one third of first vaginal births.
• Symptoms may start months after birth.

Women have leakage of flatus, liquid or formed stool, urgency, soiling of underwear and sometimes constipation with overflow. A perineal scar and a lax anal tone may be found.

• Urgency with inability to defer.
• Reduced squeeze pressure on rectal examination.
• Differential diagnosis: diarrhoea from infection or medication, overflow from constipation, rectal prolapse, rectovaginal fistula, inflammatory bowel disease, neurological disease, anal sphincter defect.
• Complications: skin irritation, social isolation, depression, sexual dysfunction, avoidance of leaving the home, worsening incontinence with age.

The approach is history, examination and imaging of the sphincter.

• Bowel diary; severity score (Wexner score); onset and relation to the birth.
• Inspect perineum for scars and gaping; digital rectal examination for resting tone and squeeze (reduced squeeze suggests sphincter defect); anoscopy.
• Endo-anal ultrasound (a defect confirms an anatomical injury), anorectal manometry and pudendal nerve tests where available.
• Stool tests and full blood count if diarrhoea; colonoscopy if bleeding or age above 45 years.

The principle is to control stool consistency, train the pelvic floor and refer for repair when a sphincter defect is found.

• Supportive: dietary fibre 25 to 30 g daily; fluids 2 to 3 litres; avoid caffeine, alcohol, spicy foods and sorbitol; pelvic floor and sphincter exercises with biofeedback (3 sets of 10 contractions daily for 3 to 6 months); scheduled toileting after meals; skin care with barrier cream; perineal pads.
• Pharmacological: ispaghula husk 3.5 g oral 12-hourly with water; loperamide 2 mg oral after each loose stool (maximum 16 mg in 24 hours) for loose stool; lactulose 15 mL oral 12-hourly for hard stool with overflow; zinc oxide barrier cream applied after each bowel movement.
• Procedures: sphincteroplasty (overlapping repair) by a trained colorectal or obstetric surgeon after 3 to 6 months for a defect with symptoms that persist despite conservative treatment; sacral nerve stimulation or injectable bulking agents for failure of other measures; colostomy for severe intractable cases.
• Special groups: women with a third or fourth degree tear are advised that elective caesarean section is an option in the next birth if symptoms persist or anal pressures are low, and vaginal birth is reasonable if they have no symptoms.
• Red flags: rectal bleeding, change in bowel habit with weight loss, faeces from the vagina (fistula), new neurological symptoms, severe perianal pain, fever.
• Follow-up: review at 6 weeks and 3 months with a repeat bowel diary; referral to a colorectal surgeon by 6 months if symptoms persist; review before any later pregnancy.