Bisacodyl

How it works

It stimulates the enteric nerves of the colonic wall to increase peristalsis and promotes fluid and electrolyte accumulation in the bowel lumen.

Prescribing in practice

• Do not use where intestinal obstruction, ileus, or undiagnosed acute abdominal symptoms are suspected, as stimulant laxatives can be harmful in these settings.
• Avoid prolonged or excessive use, which may lead to fluid and electrolyte disturbance, particularly hypokalaemia.
• Suppositories act rapidly and may cause local rectal irritation, while oral tablets should be swallowed whole and not taken with milk or antacids.

Monitoring

Monitor for adequate bowel response, abdominal pain, and electrolyte disturbance with prolonged or high-dose use.

Counselling the patient

• Oral tablets usually work overnight, while suppositories work within an hour.
• Drink plenty of fluids and use it only for short periods.
• Stop and seek advice if you develop severe abdominal pain.

Evidence & guidelines

Bisacodyl is a long-established stimulant laxative widely used for constipation and bowel preparation, with efficacy supported by clinical experience.