Chapter 13 — Pregnancy, Postpartum, and Pelvic-Floor Anorectal Disease

Purpose: pregnancy multiplies anorectal symptoms; most respond to simple, safe measures — know which drugs and procedures to avoid, and never miss sphincter injury after childbirth.

🎨 INFOGRAPHIC / VISUAL BLUEPRINT — CHAPTER 13

• Chapter colour palette: Sea Green (#0F766E) header bar, Mint Foam (#F0FDFA) panels, Deep Teal (#134E4A) text.
• Hero graphic: A timeline ribbon across the trimesters, delivery, the 6-week postpartum check, and the first year — with the typical problem at each stage (constipation, haemorrhoids, thrombosed external haemorrhoid, fissure, OASIS-related incontinence) and a green/amber/red medication strip beneath.
• Icon set: Pregnant silhouette, fibre bowl, pill with tick and cross, feeding bottle (breastfeeding), pelvic-floor sling, left-lateral tilt arrow, stethoscope.
• Bedside aphorism banner: “Treat the constipation and most pregnancy proctology treats itself.”

1. Common Problems in Pregnancy and After Delivery

Table 13.1 — Problems and first-line care

2. Pregnancy-Safe Prescribing Table

Classification reflects common international practice [C]. Always confirm with the national formulary or a pregnancy and lactation resource (for example LactMed) and the obstetric team [L].

Table 13.2 — Medicines in pregnancy and breastfeeding

3. Procedures in Pregnancy

Table 13.3 — What is safe, and when

4. Postpartum Constipation, OASIS, and Faecal Incontinence

• After any perineal repair — especially OASIS — prescribe laxatives and give analgesia to avoid straining (RCOG Green-top 29) [C]. Avoid codeine and tramadol while breastfeeding.

• Ask about continence at every postnatal check (gas, liquid, solid, urgency). New symptoms need pelvic-floor physiotherapy, perineal or colorectal clinic review, and endoanal ultrasound where available.

• Stool or wind passing from the vagina suggests a rectovaginal fistula — urgent specialist referral.

• Future deliveries: women with previous OASIS should be counselled about mode of delivery; persistent symptoms or abnormal anal physiology may favour caesarean section (RCOG Green-top 29) [C].

Algorithm 13.1 — Pregnant or postpartum patient

[PREGNANT OR POSTPARTUM PATIENT WITH ANORECTAL SYMPTOMS]
|
+-- RED FLAGS? fever + perianal pain (abscess), heavy
|   bleeding, abdominal pain or contractions, sepsis
|     -> same-day surgical review + inform obstetrics;
|        drain abscesses promptly; left tilt after 20 wk
|
+-- CONSTIPATION (the root of most symptoms)
|     -> fibre + fluids -> lactulose or macrogol
|        -> short-term senna or bisacodyl if needed
|        AVOID: sodium phosphate enemas, castor oil,
|        oral liquid paraffin
|
+-- HAEMORRHOIDS or FISSURE
|     -> conservative: fibre, softeners, warm sitz baths,
|        topical lidocaine, hydrocortisone <= 2 weeks
|     -> thrombosed external < 72 h + severe pain:
|        excision under local anaesthetic is acceptable
|     -> defer banding, LIS, and botulinum toxin until
|        after delivery
|
+-- POSTPARTUM: OASIS or new leakage or urgency?
      -> laxatives; analgesia (no codeine if breastfeeding)
      -> perineal clinic, pelvic-floor physiotherapy,
         endoanal ultrasound; counsel on future delivery
      -> stool or wind from the vagina -> urgent referral
         (rectovaginal fistula)

5. Dangerous Mimics

Table 13.4 — Pregnancy and postpartum mimics

6. Role-Targeted Action Boxes

🚑 ER DOCTOR ACTION BOX

• Pregnancy never delays abscess drainage. Involve obstetrics, position with left tilt, and use local or regional anaesthesia.
• Severe pain, early thrombosed external haemorrhoid: excision under local anaesthetic is acceptable.

🩺 FAMILY MEDICINE / GP CLINIC BOX

• Start with constipation: fibre, fluids, lactulose or macrogol.
• Ask about continence at the 6-week check and refer early after OASIS.
• Check every prescription against pregnancy and breastfeeding guidance (Table 13.2).

🏥 ER & WARD NURSE CARE AND SBAR BOX

• Postnatal teach-back: laxatives, perineal hygiene, warm sitz baths, and the warning signs (fever above 38.0 °C, wound breakdown, foul discharge, leakage of stool).

💊 CROSS-SPECIALTY PRESCRIBING TRAP

• NSAIDs from 20 weeks (FDA 2020) and codeine or tramadol while breastfeeding (FDA 2017) are the commonest prescribing traps.
• Doxycycline, ciprofloxacin, and castor oil should not be used in pregnancy.

⛔ NEVER DO THIS

• Never delay drainage of a perianal abscess because a patient is pregnant.
• Never band haemorrhoids routinely during pregnancy.
• Never prescribe codeine or tramadol to a breastfeeding mother.
• Never dismiss postpartum incontinence as normal.

📝 COMMON DOCUMENTATION ERROR

• Gestation, breastfeeding status, and obstetric team involvement not recorded.
• Postnatal notes without a continence enquiry after a perineal tear.

📨 REFERRAL URGENCY BOX

The Patient in Front of You — Chapter 13 Mini-Case

🧑‍⚕️ THE PATIENT IN FRONT OF YOU

A 31-year-old woman at 34 weeks’ gestation presents with a 30-hour history of an exquisitely painful bluish lump at the anal verge. She is afebrile and constipated. Fetal movements are normal.

Step 1 Diagnose: acute thrombosed external haemorrhoid within 72 hours; no features of abscess.

Step 2 Choose with her: excision under local anaesthetic (left-tilted position) gives faster relief and is acceptable in pregnancy; conservative care is also reasonable [C].

Step 3 Treat the cause: lactulose or macrogol, fibre, fluids; paracetamol (no NSAIDs at 34 weeks).

Step 4 Inform obstetrics and safety-net for bleeding, fever, or contractions.

Board-Style Question — Chapter 13

A breastfeeding mother needs analgesia after repair of a third-degree perineal tear. Which regimen is most appropriate?

• A. Codeine 30–60 mg four times daily
• B. Regular paracetamol plus ibuprofen, with a laxative
• C. Tramadol 50 mg four times daily
• D. No analgesia, to avoid any drug exposure for the baby

Answer and explanation

• ❌ A Codeine is not recommended in breastfeeding because ultra-rapid metabolisers can expose the infant to toxic morphine levels (FDA 2017).
• ✅ B Correct. Paracetamol and ibuprofen are compatible with breastfeeding, and laxatives prevent straining on the repair (RCOG Green-top 29).
• ❌ C Tramadol carries the same breastfeeding warning as codeine (FDA 2017).
• ❌ D Untreated pain impairs mobility, voiding, and breastfeeding.

Ten-Item Rapid Revision Checklist — Chapter 13

• 01 I treat constipation first in pregnant and postpartum patients.
• 02 I use the pregnancy-safe prescribing table and check the national formulary.
• 03 I limit topical hydrocortisone to 2 weeks.
• 04 I avoid NSAIDs from 20 weeks of gestation.
• 05 I avoid codeine and tramadol while breastfeeding.
• 06 I drain perianal abscesses promptly in pregnancy.
• 07 I know early excision of a thrombosed external haemorrhoid is acceptable in pregnancy.
• 08 I defer banding, sphincterotomy, and botulinum toxin until after delivery.
• 09 I ask about continence after every perineal tear.
• 10 I refer suspected rectovaginal fistula urgently.

Five Most Dangerous Mistakes — Chapter 13

1. ⚠️ Delaying abscess drainage because of pregnancy.
2. ⚠️ Prescribing an NSAID in the third trimester.
3. ⚠️ Prescribing codeine to a breastfeeding mother.
4. ⚠️ Missing OASIS-related incontinence at the postnatal check.
5. ⚠️ Using a sodium phosphate enema in pregnancy.

Suggested Figure and Table Captions for the Medical Illustrator — Chapter 13

• Figure 13.1. Pregnancy and postpartum timeline of anorectal problems.
• Figure 13.2. Left-tilted positioning for examination after 20 weeks.
• Figure 13.3. Obstetric anal sphincter injury classification (third and fourth degree).
• Table 13.1. Problems and first-line care.
• Table 13.2. Medicines in pregnancy and breastfeeding.
• Table 13.3. Procedures in pregnancy.
• Table 13.4. Pregnancy and postpartum mimics.
• Algorithm 13.1. Pregnant or postpartum patient.