This guidance explores the dosing and monitoring advice when using high dose loperamide to reduce high stoma output or in short bowel syndrome in adults.

High Stoma Output

Some individuals with a stoma resulting from an ileostomy, jejunostomy or a colostomy, can experience a high volume of liquid from the stoma.

This can cause a leak or loss in electrolytes or salts required by the body (sodium, magnesium, potassium). These problems can be managed in a number of ways, including the use of an anti-diarrhoeal medicine, such as loperamide.

Use in patients with short bowel syndrome without a stoma

Loperamide may also be used in individuals with short bowel syndrome without a stoma or in individuals with a high output fistula (a ‘tunnel’ or connection that forms naturally between the bowel and the surface of the skin).

A treatment summary in the British National Formulary (BNF) provides further details about use of loperamide, including use at high doses (unlicensed), for short bowel syndrome.

How loperamide works

Loperamide is a medicine commonly used to treat diarrhoea.

It is related to opioids and is often referred to as an antimotility medicine. This is because it acts on the muscle found in the small intestine to slow down bowel transit (the passage of food through the gut).

Slowing bowel transit means there is more time for water and electrolytes to be absorbed. This helps to thicken and firm up stools which prevents diarrhoea and the loss of fluids and electrolytes.

Loperamide is generally preferred over other opioid medicines used as antimotility medicines, such as codeine, as it usually works better and has fewer side effects.

Dosing and administration

Why high doses of loperamide are needed

Individuals with a short bowel or a high stoma output are more likely to have a faster bowel transit of loperamide. This can reduce how much loperamide their body absorbs, and higher doses may be required to overcome this disruption.


The use of loperamide to reduce stoma output or in short bowel syndrome is outside of its agreed manufacturers licence (off-label).

Doses used in clinical practice

There are not many good quality clinical trials on this use of loperamide reported in the medical literature.

However, there is a significant amount of experience among specialists, who often recommend using doses higher than the usual maximum licensed daily dose of 12mg to 16mg.

Therefore, dosing advice is mainly drawn from specialist experience, rather than clinical trials.

Although it may vary, the usual starting dose is 2mg to 4mg four times a day. This can then be increased by a further 2mg per dose (8mg per day) until the stoma has reached the desired consistency. The lowest effective dose should be used.

The British Society of Gastroenterology guidelines for the management of patients with a short bowel suggest that 12mg to 24mg four times a day of loperamide may be required. This would equate to a maximum daily dose of 96mg. Some specialists advise that doses above 12mg four times a day (total of 48mg daily) are rarely required.

No improvement seen despite high doses

Some people may need an additional antimotility agent such as codeine.

If stoma output continues to increase despite antimotility treatments, seek advice from a specialist, as there may be a possibility of a bowel obstruction (blockage).

When to take loperamide

Individuals should aim to take loperamide 30 to 60 minutes before food, when bowel transit (the passage of food through the gut) is slower.


Although generally well tolerated, taking high doses of loperamide can increase the risk of side effects or toxicity.

There have been reports of life-threatening adverse effects of the heart with the use of high doses. These reports have been mainly from large overdoses, or from misuse or abuse of high doses of loperamide.

It is important to note that these reports are not in patients taking loperamide for high stoma output or short bowel syndrome, although there are occasional reports in individuals taking high doses for chronic diarrhoea due to other causes.

QT prolongation

An additional concern for individuals with high stoma output is that, due to their intestinal losses, they may have salt or electrolyte disturbances, such as low magnesium or low potassium in their blood. These electrolyte disturbances may further increase their risk of changes in heart rhythms, in particular a form called QT interval prolongation, which can be life threatening.

It is not clear how much of an increase in risk there is in this group of individuals, particularly as the amount of loperamide they absorb may be reduced due to their bowel surgery or short bowel.

Other side effects

A full list of loperamide side effects at licensed doses can be found in the product summary of product characteristics (SmPC) or patient information leaflet (PIL) which you can access on the emc website.


In response to the above MHRA safety alert, the British Intestinal Failure Alliance (BIFA) published a position statement on the use of high dose loperamide in patients with intestinal failure. They recommend continuing the use of high dose loperamide (more than 16mg daily) since there is a greater risk associated with an untreated high stoma or fistula output than the risk of loperamide causing cardiac arrhythmias, but suggest that the total daily dose should be less than 80mg.

However, they recommend to:

  • Perform an electrocardiogram (ECG) to measure the QT interval of the heart in all patients starting or already taking high dose loperamide (more than 16mg in 24 hours).
  • Document the QT interval in the patients record.
  • Repeat the ECG every 3 years if the patient remains on high dose loperamide
  • Measure blood levels of loperamide in those taking more than 80mg in 24 hours or if there are serious cardiac concerns.  However, at present there is limited availability of this test in the UK, even within specialist centres.

The position statement also includes management advice if there are cardiac concerns or symptoms of loperamide toxicity. Refer to the full document for further details.

For further information around patient factors that increase the risk of drug-induced QT prolongation visit our page on ‘Identifying risk factors for developing a long QT interval’.

Management of toxicity

Individuals who show signs of loperamide toxicity, should seek urgent medical attention. Healthcare professionals can contact the National Poisons Information Service (0344 892 0111) for advice on the management of suspected loperamide toxicity.

Formulation choice

There is mixed opinion on the preferred formulation of high dose loperamide.

Although some specialists prefer orodispersible tablets or liquids, in general it seems fine to use standard capsules or tablets. The specialist gastrointestinal hospital in London (St Mark’s) uses capsules.

Opening capsules / crushing tablets (off-label use)

If needed, capsules can be opened and the contents mixed with a small amount of water, jam or yoghurt. Alternatively, the plain tablets can be crushed and mixed with water or soft food (off label). This is a useful option if individuals are seeing undigested capsules or tablets in their stool or stoma collection bag.

Liquid formulations

Liquid formulations of loperamide can cause problems for people with a high output stoma due to the high volumes that are needed to provide higher doses. Also, not all brands may be suitable. For example, Imodium® oral solution contains glycerol and artificial sweeteners which, in high amounts, may cause gastrointestinal side effects, including diarrhoea.

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