A 68‑year‑old woman with advanced breast cancer on opioids develops severe constipation with faecal loading on abdominal X‑ray. She has been on senna

Question

A 68‑year‑old woman with advanced breast cancer on opioids develops severe constipation with faecal loading on abdominal X‑ray. She has been on senna 30 mg once daily and lactulose 20 mL twice daily. The palliative care team adds macrogol (Movicol) sachets. What is the mechanism of macrogol?

Accepted Answer

Macrogol is an osmotic laxative that retains water in the bowel lumen through its osmotic properties, softening stool and increasing stool volume — unlike lactulose, it does not produce gas via fermentation.

Answer

Macrogol stimulates colonic peristalsis directly by irritating the enteric nerves.

Answer

Macrogol is a stool softener that lubricates faeces without altering water content.

Answer

Macrogol works by irritating the bowel mucosa to induce bowel movements.

Answer

Macrogol is administered as an enema rather than as an oral solution.

Macrogol Mechanism of Action — SCE Palliative Medicine MCQ

A 68‑year‑old woman with advanced breast cancer on opioids develops severe constipation with faecal loading on abdominal X‑ray. She has been on senna 30 mg once daily and lactulose 20 mL twice daily. The palliative care team adds macrogol (Movicol) sachets. What is the mechanism of macrogol?