Diarrhoea
First-line treatment for acute diarrhoea is to prevent dehydration.
See prescribing notes on when anti-diarrhoeals should not be given.
Due to acquisition cost loperamide capsules are preferred over tablets. For patients who cannot swallow capsules or tablets, loperamide capsules may be opened and contents dispersed in water prior to administration (off-label).
See prescribing notes on when anti-diarrhoeals should not be given.
Prescribing Notes:
- Anti-diarrhoeal drugs should not be given in patients with acute infective diarrhoea, pus or blood in stools, high fever, active inflammatory bowel disease or pseudomembranous colitis.
- Ask about recent antibiotic therapy. If antibiotics have been taken recently, avoid loperamide, and provide a worsening statement. Clostridioides difficile (C.diff) infection (CDI) causes diarrhoea as the main symptom. Most cases will have had a recent course of antibiotics. Some antibiotics have a higher risk of C. diff (e.g. co-amoxiclav, ciprofloxacin, clindamycin and cephalosporins), but any antibiotic can upset normal gut flora and result in loose stools. C. diff bacteria produce a toxin that acts on the bowel to cause diarrhoea. Anything that stops diarrhoea (e.g. loperamide/opiates) results in toxin retention and potentially worsening disease.
- Faecal impaction can give rise to “overflow diarrhoea” and must be excluded as part of the differential diagnosis.
- Anti-motility drugs should not be given to patients experiencing overflow diarrhoea.
- Older patients with acute or prolonged diarrhoea are particularly likely to require fluid replacement.
- Loperamide is preferred to codeine phosphate because it is less likely to produce central side effects and addiction.
- Codeine is recommended only in short-term use due to CNS side effects and dependence.
History Notes
15/04/2026
Regional formulary chapter launched.
See prescribing notes on when anti-diarrhoeals should not be given.
Due to acquisition cost loperamide capsules are preferred over tablets. For patients who cannot swallow capsules or tablets, loperamide capsules may be opened and contents dispersed in water prior to administration (off-label).
Prescribing Notes:
- Anti-diarrhoeal drugs should not be given in patients with acute infective diarrhoea, pus or blood in stools, high fever, active inflammatory bowel disease or pseudomembranous colitis.
- Faecal impaction can give rise to “overflow diarrhoea” and must be excluded as part of the differential diagnosis.
- Anti-motility drugs should not be given to patients experiencing overflow diarrhoea.
- Loperamide is preferred to codeine phosphate because it is less likely to produce central side effects and addiction.
- Bulk forming drugs, such as ispaghula are useful in controlling diarrhoea associated with diverticular disease.
History Notes
15/04/2026
Regional formulary chapter launched.
History Notes
15/04/2026
Regional formulary chapter launched.