1.4 Acute diarrhoea

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, see Gastro-intestinal tract infections

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.

1.4.2 Antimotility drugs

  • Capsules 2mg (£0.90 = 30 capsules)
  • Tablets 2mg (£2.24 = 30 tablets)


  • Acute diarrhoea; adjunct to rehydration in acute diarrhoea in adults; chronic diarrhoea in adults only


  • Acute diarrhoea: 4mg initially followed by 2mg after each loose stool for up to 5 days; usual dose 6–8mg daily; maximum 16mg daily
  • Chronic diarrhoea in adults: initially, 4-8mg daily in divided doses, subsequently adjusted according to response and given in 2 divided doses for maintenance; maximum 16mg daily


  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 tablets and 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, or the plain tablets can be crushed and mixed with water or soft food (off label).
  2. The maximum dosage for loperamide is 16mg daily (8 capsules), although stoma patients may require higher doses.
Codeine phosphate


  • Acute diarrhoea


  • Acute diarrhoea: 30mg 3–4 times a day; usual dose 15–60mg 3–4 times a day


  1. Codeine has addictive properties and should be reserved for short courses only.
  2. Codeine should be reserved for short courses and best avoided in stoma patients.


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