3rd / 4th-degree tear (OASI) repair

Steps

1. Theatre, regional/GA, good light; trained operator.
2. Classify with rectal exam (3a, 3b, 3c, 4); count.
3. Anorectal mucosa: 3-0 polyglactin, continuous or interrupted.
4. Internal sphincter: separately, end-to-end, 3-0 PDS (or 2-0 polyglactin).
5. External sphincter full thickness: overlap or end-to-end (equal results). Partial (3a / some 3b): end-to-end.
6. Bury knots under superficial perineal muscles.
7. Repair perineal muscle, vagina and skin as for a 2nd-degree tear.
8. Rectal + vaginal exam; final count.

Afterwards

• IV broad-spectrum antibiotic, then oral course (e.g. co-amoxiclav)
• Laxatives ~10–14 days; avoid codeine
• Catheter ~12 h; physiotherapy
• Review at 6–12 weeks; discuss mode of next birth