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.
For bowel cleansing - increased risk of infection if clinically indicated and not given pre-operatively.
For bowel cleansing - dehydration may occur in patients with reduced fluid intake or those at risk of electrolyte imbalance complications (i.e. frail, elderly, renally impaired) when given pre-operatively – see Further Information.
Advice in the perioperative period
Elective surgery
Continue, if required.
EXCEPT:
- for patients having bowel cleansing preparations prior to surgery – stop when bowel preparation starts.
Pre-operative use of Klean-Prep®, Moviprep®, Plenvu® or Vistaprep® for bowel cleansing
Bowel cleansing preparations are used to prepare the bowel for endoscopy, radiological procedures, or surgery that requires a clean bowel.
Patients should be assessed for the suitability of bowel cleansing preparations and be fully counselled on the correct procedure to follow for the bowel preparation that they have been given – see Further information.
Check renal function and electrolytes prior to commencing bowel preparation.
Patients with diabetes mellitus
Patients who take medication for diabetes mellitus and require bowel cleansing preparations will require alterations to their medication whilst they have an altered diet or are fasting. NHS Trusts or Health Boards should have agreed guidance for patients undergoing any procedure that requires the use of bowel cleansing preparations.
Patients taking laxatives
Patients who take regular laxatives should be advised to stop taking these while they are taking bowel cleansing preparations.
Patients taking non-steroidal anti-inflammatory drugs (NSAIDs)
Where possible NSAIDs should be discontinued on the day of administration of any oral bowel cleansing preparation and withheld until 72 hours after the procedure – see Interactions with other common medicines in the perioperative period.
Emergency surgery
Continue, if required.
EXCEPT:
- for patients with suspected bowel obstruction or perforation
- for patients who are unable to tolerate the volume of fluid required for safe administration.
Pre-operative use of Klean-Prep®, Moviprep®, Plenvu® or Vistaprep® for bowel cleansing
If there is time, and it is safe for the patient to use bowel cleansing preparations prior to emergency surgery, follow the advice as for elective surgery.
Post-operative advice
Resume post-operatively, if needed, once enteral intake resumed.
Due to the volume of water required to reconstitute macrogol laxatives, review if the patient is nil by mouth or under a fluid restriction in the post-operative period.
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.
Review if patient develops reduced gastrointestinal motility (e.g. ileus) post-operatively.
Patients undergoing colorectal surgery
Review the need for macrogol laxatives post-operatively.
Patients undergoing head and neck surgery
For patients undergoing head and neck surgery who have dysphagia post-operatively and require macrogol laxatives, care should be taken to ensure doses are administered appropriately if there is a need to use thickening agents to support swallowing – see Further information.
Post-operatively following use of Klean-Prep®, Moviprep®, Plenvu® or Vistaprep® for bowel cleansing
Check renal function and electrolytes post-operatively.
Interactions with common anaesthetic agents
None.
Interactions with other common medicines used in the perioperative period
The absorption of other medicinal products could be reduced due to an increase in gastrointestinal transit rate induced by macrogol laxatives. There have been isolated reports of decreased efficacy with some concomitantly administered medicines. Hence, other medicines should not be taken orally for one hour before and one hour after taking macrogol laxatives.
Bowel cleansing
Bowel cleansing preparations increase gastrointestinal transit rate and as a result absorption of oral medication may be reduced if taken alongside bowel preparation products. Oral medication should be avoided at least one hour before and after administration of bowel cleansing preparations.
Non-steroidal anti-inflammatory drugs (NSAIDs)
NSAIDs reduce renal perfusion and therefore limit the kidney’s capacity to compensate for reduced renal perfusion through potential volume depletion that may occur with bowel cleansing preparations. Where possible, NSAIDs should be discontinued on the day of administration of any oral bowel cleansing preparation and withheld until 72 hours after the procedure; however, a single intra-operative dose may be given at discretion of anaesthetist as part of multi-modal analgesia approach (providing patient is adequately hydrated and no significant comorbidities, e.g. frailty, renal impairment).
Further information
MHRA/CHM advice: Polyethylene glycol (PEG) laxatives and starch-based thickeners: potential interactive effect when mixed, leading to an increased risk of aspiration (April 2021)
Addition of a macrogol (PEG)-based laxative to a liquid that has been thickened with a starch-based thickener may counteract the thickening action, resulting in a thin watery liquid that, when swallowed, increases the risk of potentially fatal aspiration in patients with dysphagia. Healthcare professionals are advised to avoid directly mixing macrogol-based laxatives with starch-based thickeners, especially for patients with dysphagia who are considered at risk of aspiration.
Safe prescribing of bowel cleansing preparations
In 2009 the NPSA issued a Rapid Response Report on the potential risk of harm associated with use of oral bowel cleansing preparations. Death and harm from electrolyte abnormalities, dehydration and serious gastrointestinal problems have been associated with the use of bowel cleansing preparations prior to surgery and/or investigative procedures. Frail and debilitated elderly patients and those with contraindications (e.g. renal impairment) are particularly at risk.
NHS Trusts or Health Boards should have safeguards in place to reduce the risk, ensuring that a clinical assessment of each patient for contraindications and risk takes place, that the use of a bowel cleansing preparation is authorised by a clinician, that an explanation on the safe use of the preparation is provided to the patient, and that a safe system exists for the supply of preparation to each patient.
References
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed 26 March 2024]
Connor A, Tolan D, Hughes S et al. Consensus guidelines for the safe prescription and administration of oral bowel-cleansing agents. Gut. 2012,61:1525-1532 DOI:10.1136/gutjnl-2011-300861
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press http://www.medicinescomplete.com [Accessed 26 March 2024]
Macrogols. In: Brayfield A (Ed), Martindale: The Complete Drug Reference. London: The Royal Pharmaceutical Society of Great Britain. http://www.medicinescomplete.com [Accessed 30 April 2024]
National Institute for Health and Care Excellence. Surgical site infections: prevention and treatment. NICE Guideline 125. Accessed via https://www.nice.org.uk/guidance/ng125 26/03/24. Published 19 August 2020
National Patient Safety Agency (NPSA). Rapid Response Report (NPSA/2009/RRR012). Reducing the risk of harm from oral bowel cleansing solutions. 19tFebruary 2009. Accessed on 25 March 2024 via nationalarchives.gov.uk
Summary of Product Characteristics – Compound Macrogol Oral Powder Sugar Free. Galen Limited. Accessed on 26 March 2024 via www.medicines.org.uk. [Date of revision of the text November 2021]
Summary of Product Characteristics – Plenvu® powder for oral solution. Norgine Limited. Accessed on 26 March 2024 via www.medicines.org.uk. [Date of revision of the text September 2023]
Summary of Product Characteristics – MOVIPREP® powder for oral solution. Norgine Limited. Accessed on 26 March 2024 via www.medicines.org.uk. [Date of revision of the text December 2022]