Perineal Tear Through the Anal Sphincter: How Repair Is Done, What to Expect, and How to Protect the Repair

Birth-related tears are graded by how deep they go:

• Third-degree tear (OASIS): involves the external anal sphincter (EAS).
  • 3a: <50% of EAS torn
  • 3b: ≥50% of EAS torn
  • 3c: EAS and the internal anal sphincter (IAS) torn
• Fourth-degree tear: extends through the external anal sphincter and internal anal sphincter into the rectal mucosa (the lining of the back passage).

Because the anal sphincters preserve gas and stool continence, accurate diagnosis and meticulous repair in an operating theatre (not at the bedside) are essential. Post-repair care—especially bowel management—is just as important for outcomes as the stitches themselves.^[1]

After delivery, the clinician inspects the perineum under good lighting with gloved digital rectal examination and, when needed, a small anoscope to look for rectal mucosal tears. Any doubt about depth → treat as higher grade and repair in theatre. Classification guides which layers must be repaired (internal anal sphincter versus external anal sphincter; rectal mucosa in fourth-degree), the suture choice, and the overlap vs end-to-end technique.^[2,3]

• Operating theatre (or dedicated procedure room) with sterile setup, good lighting, and appropriate instruments.
• Regional anesthesia (spinal or epidural top-up) or general anesthesia so the pelvic floor is relaxed and pain-free; this improves visualization and suture accuracy.
• Antibiotic prophylaxis (single peri-operative dose covering anaerobes) reduces wound infection and dehiscence.^[4]

• Closed first, typically with a monofilament absorbable suture in a continuous, non-locking fashion to create a watertight seal. Avoid figure-of-eight stitches (they can strangulate tissue).

• The internal anal sphincter is a pale, smooth band deep to the EAS. It is repaired separately with interrupted end-to-end sutures (monofilament absorbable), restoring the internal continence ring. Separate Internal anal sphincter repair is linked to better continence outcomes.^[5]

Two accepted techniques:

• End-to-end approximation: bring the cut ends together and stitch them edge to edge with several interrupted sutures. Often chosen for partial-thickness (3a/3b) tears.
• Overlap repair: mobilize the external anal sphincter ends and overlap one over the other before suturing. Commonly used for full-thickness tears.

Randomized trials show comparable outcomes overall; choice depends on tear pattern and surgeon experience. The key is tension-free, well-vascularized repair with a delayed-absorbable suture (e.g., 2-0 or 3-0).^[6]

• Reconstruct the perineal body (bulbospongiosus, superficial transverse perineal muscles) with interrupted sutures.
• Vaginal mucosa and skin are closed last, typically with a continuous absorbable suture.
• Rectal exam at the end confirms no suture has inadvertently trans-fixed the rectal mucosa.

Grade of tear, layers repaired, technique (end-to-end vs overlap), suture types, antibiotics given, and postoperative orders (bowel regimen, pain control, physiotherapy referral) are recorded. Women receive written aftercare.^[1]

Pain control and swelling

• Ice packs to the perineum in the first 24 hours, then warm sitz baths from day 2–3 for comfort and hygiene.
• Multimodal analgesia (paracetamol/acetaminophen ± non-steroidal anti-inflammatories if safe). Avoid strong constipating opioids where possible.^[9]

Bowel regimen (crucial)

• Stool softeners (e.g., docusate) and an osmotic laxative (e.g., polyethylene glycol or lactulose) are standard for 10–14 days. The goal: soft, formed stool that passes without straining. This is one of the strongest predictors of a comfortable recovery.^[7]

Bladder care and thrombosis prevention

• Early catheter removal once mobile; encourage ambulation and hydration. Thromboprophylaxis according to obstetric risk policy.^[8]

Breastfeeding considerations

• Most first-line pain medicines and laxatives used here are compatible with breastfeeding; clinicians choose agents with excellent lactation safety profiles.^[9]

• Keep stools soft-formed with daily osmotic laxative and adequate fluids (aim for pale-yellow urine).
• Add soluble fiber (psyllium or methylcellulose) if stools are loose, or increase osmotic laxative if too firm.
• Toilet posture: feet on a small stool, elbows on knees, lean forward, belly relaxed, and do not hold your breath—exhale gently as you pass stool.

• Warm sitz baths 1–2×/day (10 minutes) from day 2–3; pat dry; use a peri-bottle after urination/defecation.
• Change pads frequently; keep the area dry between soaks.
• Report increasing pain, discharge, or fever (infection signs).

• Walk daily; avoid lifting heavier than the baby + carrier for 2 weeks, then build gradually.
• When you feel a cough or sneeze, hug a pillow to the perineum for counter-pressure.
• No vaginal penetration, tampons, or swimming until cleared (commonly 6 weeks).

• Early focus is on breath-coordinated pelvic-floor relaxation, gentle contract-relax awareness, and scar comfort; formal strengthening begins once pain settles (often after the 6-week review).
• Evidence supports specialist pelvic-floor rehab for continence and sexual comfort after obstetric anal sphincter injuries.^[10]

• Pain should be intermittent and mild; stitches largely dissolved.
• Bowel movements are comfortable without straining; many continue a smaller maintenance dose of osmotic laxative or fiber for predictability.
• Pelvic-floor training progresses to endurance holds and functional drills (e.g., pre-cough “squeeze before you sneeze”).
• Sex: start when comfortable (often after 6–8 weeks). Use lubricant, go slowly, and try side-lying positions initially. Pain that persists warrants pelvic-floor review and, if needed, topical therapies.

Most people regain gas control and confidence first; urgency with loose stool takes longer and improves as consistency stabilizes. If you notice new leakage, urgency, or flatal incontinence beyond 8–12 weeks, ask for endoanal ultrasound and anorectal manometry to check muscle integrity and coordination.^[11]

Do I Really Need Antibiotics?

A single peri-operative dose reduces infection and wound breakdown; prolonged courses are not routinely required unless infection develops.^[4]

Which Repair is Better—Overlap or End-to-End?

Both are acceptable. Outcomes are similar when used for the right tear pattern and performed meticulously. Separate IAS repair (when torn) is key.^[6]

How long do I need a laxative?

Plan 10–14 days routinely, then tailor. The aim is soft-formed stool without straining. Some continue low-dose fiber longer for comfort.^[7]

When can I run or lift weights?

After your 6–12 week review, if continence is good and pelvic-floor endurance is adequate. Build gradually with physio guidance.

What if I leak gas or stool after 3 months?

Ask for a specialist clinic assessment (urogynecology/colorectal). Options include targeted pelvic-floor therapy, biofeedback, bowel-consistency strategies, and in selected cases sphincter re-repair or advanced procedures.^[11]

• Fever, rapidly increasing perineal pain, purulent discharge, or wound opening
• Inability to pass stool with severe pain despite laxatives
• Sudden, persistent fecal incontinence or new neurological symptoms (leg weakness, numbness)
• Heavy rectal bleeding

These signs need prompt review to prevent complications or repair failure.

• Counseling is individualized: Many can consider vaginal birth again—especially if symptom-free with normal manometry and endoanal ultrasound.^[11]
• Consider planned cesarean if you have ongoing anal incontinence, significant sphincter defects on imaging, or severe anxiety about recurrence.
• Skilled intrapartum care reduces risk: perineal support, warm compresses, and judicious mediolateral episiotomy in instrumental deliveries can lower severe-tear rates.^[12]

• Soft stools for two weeks (osmotic laxative + fluids); never strain.
• Sitz baths daily after day 2–3; keep the area clean and dry.
• Hug a pillow when coughing/sneezing for support.
• Pelvic-floor physio early; progress to functional endurance.
• Ask for help early if you notice leakage, urgency, or pain with sex.
• Attend your 6–12 week review; request anal sphincter imaging if symptoms persist.

Anal sphincter tears are daunting—but with theatre-based, layered repair, separate internal anal sphincter repair when torn, appropriate antibiotics, and a no-strain bowel routine, outcomes are usually excellent. Add pelvic-floor rehabilitation, smart perineal care, and timely follow-up, and most people return to continence, comfort, and confidence—often within the first three months. Future births are a shared decision based on symptoms and imaging, not fear alone.

References: