Second-lineSenokot / Dulcolax
Senna / Bisacodyl
Stimulant laxatives
Short-term rescue when osmotic laxatives fail — third-trimester friendly.
OralRectal (bisacodyl suppository)
First-line for
- Opioid-induced constipation postpartum
- Refractory pregnancy constipation (short courses)
Mechanism
Colonic stimulants — activate enteric nerves and ↑ water/electrolyte secretion; take effect 6–12 h.
"Stimulant = short-term"
- Combine with an osmotic — don't rely alone
- Suppository works in 15–30 min
- Avoid chronic use
Dosing
- Senna
- 7.5–15 mg PO at bedtime
- Bisacodyl PO
- 5–10 mg at bedtime
- Bisacodyl PR
- 10 mg suppository in the morning
Contraindications
- AbsoluteIntestinal obstruction
- CautionChronic use → colonic atony
Side effects
- Cramps
- Diarrhoea
- Hypokalaemia with chronic use
- Yellow-brown urine (senna)
Fetal & maternal notes
- • Minimal absorption; no teratogenic signal
- • Compatible with breastfeeding
Key interactions
Digoxin
CautionHypokalaemia potentiates toxicity
Clinical pearls
- 💡 Add stimulant on top of osmotic + docusate for opioid-induced postpartum constipation
Content last reviewed: REPLACE_ME (e.g. 2026-07)
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