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Colestyramine for bile acid malabsorption (BAM) after stomach / gullet surgery

Patient information A-Z

What is Bile Acid Malabsorption?

Bile acid malabsorption is a condition where bile acids (a part of your body’s natural digestive system, also referred to as bile salts) are incompletely reabsorbed in your bowels, resulting in diarrhoea.


To treat your post-operative diarrhoea, we have prescribed a medicine called colestyramine. This is because there is a possibility that your diarrhoea is due to the bile salts in your gut being poorly re-absorbed, resulting in loose motions. Colestyramine works by binding these bile salts in a way that stops them causing diarrhoea.

How to take colestyramine

Colestyramine comes in 4g sachets. Take ONE sachet daily. The dose might be increased but only on the advice of a clinician.

How to make up the sachets

  1. The contents of one sachet should be sprinkled evenly onto 150 ml (4 - 6 fluid oz) of water, fruit juice, skimmed milk, thin soups, fruit smoothies or sauces (e.g. apple sauce).
  2. Allow to stand for 1 or 2 minutes.
  3. Once the powder has soaked into the liquid, stir or shake it to mix in thoroughly.

Do not take this medicine in its dry form as it might cause you to choke.

Taking other drugs / vitamins with colestyramine

You should not take any other medicines, and particularly your multi-vitamins and minerals, one hour before or four hours after a dose of colestyramine, as it may prevent absorption of the other medicines. This will require you to plan your daily medication/vitamin/mineral schedule if you are taking several drugs and / or vitamins.

Are there any risks associated with colestyramine?

There are no specific risks associated with colestyramine. However, as it can interfere with absorption of some vitamins, testing for this will form part of your routine post-surgery, micronutrient blood tests so we can quickly identify it if this becomes a problem. It is important that you take a regular multi-vitamin and mineral as recommended.

How do I know whether to stop or continue treatment?

It might take some weeks for any effect of colestyramine to be noticed. If you don’t notice an improvement in symptoms after four weeks, there is likely no benefit in continuing the colestyramine and it can be stopped as directed by your clinician. If your symptoms completely improve, then you can continue colestyramine at the prescribed dose. If you experience some, but not complete, improvement, the dose can be increased after discussion with a clinician.

Side Effects

Like all medicines, colestyramine can cause side effects, although not everybody experiences them.

The most frequent side effect is constipation, but usually reduces over time, and is why you will start with a low dose and increase it slowly, until you are taking the full number of sachets as prescribed by your clinician.

Further information is available in the patient information leaflet supplied with your medicine.

Contacts and further information

Upper GI specialist nurses
Telephone 01223 596383

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151