Question: how long does antidiarrheal take to work?
Answer: Loperamide usually starts to work within 1 hour to make your diarrhoea better. How long will I take it for? Most people only need to take loperamide for 1 to 2 days. You may need to take it for longer if your diarrhoea is because of a bowel problem such as Crohn's disease, ulcerative colitis or short bowel syndrome.