Oral bowel preparation agents

You may have seen the recent letter from QA asking that we prescribe bowel prep for patients going to endoscopy. This guideline gives advice on how you can safely do this.

Portsmouth prefers Picolax (contains sodium picosulphate and magnesium citrate) and Klean Prep (contains polyethylene glycol). Generally Picolax is used if possible as patients tend to prefer it. I will therefore summarise some of the issues with these two products and some other things to be aware of – but this is by no means exhaustive!

Picolax. Ideally use only if GFR is > 60. It can be used if GFR is lower, but only if Klean Prep isn’t tolerated. Be very cautious if they are CKD 4 or 5. Use with caution if the patient is at risk of hypovolaemia (as below). Avoid if they have liver failure or cirrhosis.

Patients can get hypermagnasaemia and hyponatraemia from its use.

Klean Prep. It tastes horrible and is a large volume of fluid to drink, but generally is safe. The patient must stick to the advice on fluid intake to avoid getting dehyrdrated, or getting water overload. Advise the patient to stop the Klean Prep if their stools become clear and watery, though  they should continue to drink water.

Want to use something else? Be aware that these medications can have serious side-effects so check the BNF carefully before using.

The following should make you cautious:

  • Patients at risk of hypovolaemia (eg on diuretics, with renin-angiotensin blockade from ACEi or A2RBs, with CCF, cirrhosis or CKD) will be more likely to suffer side-effects.
  • Renal disease. Any patient with CKD, or at risk of CKD, needs to have had UE done in the last 3m. Post-transplant or dialysis patients should be discussed with the renal team.
  • Bowel Problems. An ileostomy is an absolute contraindication.
  • ACEi / A2RBs. Stop 72 hrs before using the preparation.
  • Diuretics. May need to stop if possible. If continue, check UE carefully.
  • NSAIDs. Stop on day and for 72 hrs after procedure if possible. This is because of their renal effects. Aspirin can continue.
  • Admission? Some patients require admission, eg people who must carry on certain medications (eg transplant patients), type 1 diabetics and the very frail.

Louise Hudman

I'm a freelance GP locum in Winchester & Southampton locum chambers, and Pallant Medical Chambers Clinical Guidelines Lead Partner.

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2 Responses

  1. Alan Sim
    See Local Services section of the Portsmouth Microsite regards this subject - and letters attached. I believe the CCG and LMC were not very happy about GPs being forced to take this on and my understanding is that the plan was withdrawn. Having said that, I think one of the referral forms does have a tick box asking us to ensure patient is fit for bowel prep - so this is still very useful info. Thanks Louise.
  2. Susan Stone
    Really useful, especially what to do if taking nsaids and ACEi, thanks! Dr Su Stone 07500 871130 drsustone@googlemail.com

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