UK Clinical Pharmacy Association

Glycerol (Glycerin)

Issues for surgery

Risk of constipation if omitted, particularly in patients with chronic laxative use, which may further be exacerbated by medication administered perioperatively, e.g. opioids.

Advice in the perioperative period

Elective surgery

Continue, if required.


  • for patients having bowel cleansing preparations prior to surgery – stop when bowel preparation starts.

Emergency surgery 

Continue, if required.


  • for patients with suspected bowel obstruction or perforation.

Post-operative advice

Resume post-operatively, if needed.

If concomitant use of opioids or other medication that may cause constipation, or antibiotics that may cause diarrhoea, monitor response to treatment and adjust dose accordingly.

Patients undergoing colorectal surgery

Review the need for stimulant laxatives post-operatively.

Use of suppositories following certain types of colorectal surgery are not recommended; confirmation should be sought from the colorectal team before prescribing if stimulant laxatives are required post-operatively.

Interactions with common anaesthetic agents


Interactions with other common medicines used in the perioperative period


Further information

None relevant.


Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. [Accessed 23 March 2024]

Glycerin Suppositories BP 4g Adult Size. Thornton & Ross Ltd. Accessed via 23/03/24 [date of revision of the text January 2015]

Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press [Accessed on 23 March 2024]