Glycerol Suppositories

How it works

Inserted into the rectum, glycerol acts osmotically to draw water into the bowel and has a mild local irritant and lubricant effect that stimulates rectal evacuation.

Prescribing in practice

• They are for occasional, short-term use only and should not be relied upon long term, as the underlying cause of constipation should be addressed.
• Moistening the suppository before insertion improves comfort, and onset of action is usually rapid.
• Avoid in patients with bowel obstruction or undiagnosed rectal bleeding until assessed.

Monitoring

No routine laboratory monitoring is needed; assess the clinical response and review if constipation persists or recurs.

Counselling the patient

• Moisten the suppository with water before gently inserting it into the back passage and try to retain it for a short while.
• Expect the medicine to work fairly quickly; seek advice if there is no result or if you have persistent bleeding.

Evidence & guidelines

Rectal glycerol is a long-established, widely used measure for the short-term relief of constipation.