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Stimulant Laxative Pregnancy: No adequate well-controlled studies in pregnant women; long experience has shown no evidence of undesirable/damaging effects. Should not be taken in pregnancy (especially the first trimester) or during breast-feeding unless expected benefit outweighs possible risk and only on medical advice (eMC §4.6).

Bisacodyl

Brand names: Dulcolax

Bisacodyl is a stimulant laxative used for constipation and for bowel preparation before procedures.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1 to 2 coated tablets (5-10 mg)
Route: Oral
Frequency: Once daily before bedtime
Max: Maximum recommended daily dose should not be exceeded (do not use continuously for more than 5 days without investigating the cause of constipation)
eMC §4.2 (Bisacodyl 5mg Laxative Tablets, 12+ years). Adults and children over 12 years. Start with the lowest dose; may be adjusted up to the maximum recommended dose to produce regular stools. Take at night for a bowel movement the following morning; swallow whole with adequate fluid. Do not take together with products that reduce upper-GI acidity (milk, antacids, proton pump inhibitors) to avoid prematurely dissolving the enteric coating. Once regularity is restored, reduce dose and usually stop. No specific dosing information in the elderly. Should not be used in children/adolescents under 12 years. US labelling covers a suppository product (not the oral tablet): adults and children 12 years and older 1 suppository once daily.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Directions -detach one suppository from the strip -remove wrapper before inserting into the rectum adults and children 12 years of age and older 1 suppository once daily children 6 to under 12 years 1/2 suppository once daily children under 6 years do not use

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-01-15. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

  • Ileus, intestinal obstruction
  • Acute abdominal conditions including appendicitis; acute inflammatory bowel disease
  • Severe abdominal pain associated with nausea and vomiting
  • Severe dehydration
  • Known hypersensitivity to bisacodyl or any component

Side effects

  • Abdominal cramps, abdominal pain, diarrhoea, nausea (common)
  • Haematochezia (blood in stool), vomiting, abdominal/anorectal discomfort, dizziness (uncommon)
  • Anaphylactic reactions, angioedema, hypersensitivity (rare)
  • Dehydration, syncope (rare)
  • Colitis including ischaemic colitis (rare)

Interactions

  • Products reducing upper-GI acidity (milk, antacids, proton pump inhibitors) — may prematurely dissolve the enteric coating; do not co-administer

Clinical monograph

How it works

It stimulates the enteric nerves of the colon to increase peristalsis and also promotes fluid and electrolyte accumulation in the bowel lumen, softening stool and hastening transit.

Prescribing in practice

  • Avoid in intestinal obstruction, ileus, acute abdominal conditions and acute inflammatory bowel disease.
  • Abdominal cramps and discomfort are common, and prolonged excessive use can lead to fluid and electrolyte disturbance.
  • Oral tablets are enteric coated and should not be taken with milk or antacids, which can cause premature dissolution and gastric irritation.

Monitoring

No routine monitoring is needed for short-term use; with prolonged or high-dose use consider fluid balance and electrolytes, particularly potassium.

Counselling the patient

  • Tablets usually work overnight, so they are typically taken at bedtime, whereas suppositories act within about an hour.
  • Swallow tablets whole without milk or antacids close to the dose, and maintain a good fluid intake.
  • Seek advice if you have severe abdominal pain, vomiting or no bowel movement despite treatment.

Evidence & guidelines

Standard stimulant laxative option (NICE CKS constipation).

Reference: BSG Bowel Preparation Guidelines; SPC Dulcolax; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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