Drug therapy for functional diarrhoea
If drug therapy is required to treat diarrhoea, use:
loperamide 2 mg orally, 1 to 4 times daily if required. loperamide loperamide loperamide
In patients at risk of bile salt malabsorption (eg those who have had cholecystectomy or ileal resection) a trial of a bile acid sequestrant may be warranted; useSadowski, 2020:
colestyramine 4 to 8 g orally, up to twice daily if required. colestyramine colestyramine colestyramine
All other drugs should be taken at least 1 hour before, or 4 to 6 hours after colestyramine.
For patients who find colestyramine effective but unpalatable, consider referral to a gastroenterologist for a trial of colesevelam or colestipol1Camilleri, 2020.
Avoid codeine-containing preparations because of the risk of dependence. Diphenoxylate+atropine is not recommended because it can cause anticholinergic adverse effects, particularly in elderly people.