How Does Imodium Work? Diarrhoea or an 'upset' stomach occurs when something upsets the natural balance of nutrients & water absorption in the intestines & the digestive system works overtime. This causes the very frequent passing of loose, watery stools which is known as diarrhoea. The active ingredient loperamide helps to calm the digestive system down helping the body get back to normal & stop the frequency of diarrhoea by helping the stools to return to normal firmness. How To Take Imodium Capsules Adults & children aged 12 & over: 2 capsules should be taken at first. If needed, one capsule should be taken after each loose bowel movement. No more than 8 capsules should be taken a day. If diarrhoea lasts for longer than 24 hours you should consult your doctor. Diarrhoea caused through IBS (Irritable Bowel Syndrome) Confirmed cases of IBS: 2 capsules should be taken to control the episode of diarrhoea. Further capsules can be taken if required, but no more than 8 capsules should be taken a day. If symptoms persist for longer than 2 weeks, speak to your doctor. Imodium must not be given to children under 12 years old. Adverse effects are rare with the use of Imodium but consult your doctor or pharmacist if you notice any unusual symptoms.