1.4 Acute diarrhoea

1.4.2 Antimotility drugs

Fluid and electrolyte repletion is the primary treatment for acute diarrhoea and gastroenteritis.

For details of oral rehydration see 9.2.1 Oral preparations for fluid and electrolyte imbalance.

A diagnosis of the cause of diarrhoea should be made before starting symptomatic treatment. Acute prescriptions should be restricted to 30 loperamide capsules or 20 codeine tablets.

NICE CG49 (2007) addresses the management of faecal incontinence. Prescribers are advised to review patient's medication and consider alternatives to drugs that might be contributing to faecal incontinence.

For advice about the use of antibiotics in gastroenteritis, refer to Gastro-intestinal tract infections in chapter 5 of the formulary.

NHS England (NHSE) has published new prescribing guidance for various common conditions for which over the counter (OTC) items should not be routinely prescribed in primary care (quick reference guide). One of these conditions is acute diarrhoea in adults.

Many diarrhoea products; for example, loperamide 2mg capsules and oral rehydration sachets are cheap to buy and are readily available OTC along with advice from pharmacies. Some self-care medicines are available from shops and supermarkets. Please click here for further information, exceptions, and a patient leaflet.

  • Capsules 2mg (£1.01 = 30 capsules)


  • Acute diarrhoea
  • Chronic diarrhoea


  • Acute diarrhoea: 4mg initially followed by 2mg after each loose stool (maximum 16mg in 24 hours)
  • Chronic diarrhoea: 4mg-8mg per day in divided doses, adjust to symptoms (maximum 16mg in 24 hours)


  1. Loperamide oral solutionSF 1mg in 5ml was discontinued on 30th September 2022, stocks will be exhausted by late October 2022
    1. If patients can swallow solid dosage forms, loperamide capsules remain available
    2. The Specialist Pharmacy Service suggest, if needed, capsules can be opened and the contents mixed with a small amount of water, jam, or yoghurt (off label).
  2. For chronic diarrhoea, loperamide should be introduced at a very low dose and the dose should be escalated, as tolerated by the individual to achieve the desired stool consistency.
Codeine phosphate


  • Acute diarrhoea
  • Chronic diarrhoea


  • Acute diarrhoea: 30mg 3-4 times a day; dose range 15-60mg 3-4 times a day.


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