The dosage for Imodium is two capsules for initial relief and one capsule after each subsequent loose stool, reports DailyMed. Patients should not take more than eight capsules, or 16 milligrams, in a 24-hour period.
Children aged 2 to 5 should use Imodium A-D liquid instead of Imodium capsules, DailyMed. Older children up to age 12 may take either the liquid or the capsules. Patients with diarrhea should drink water and fluids with electrolytes to avoid dehydration. Loperamide hydrochloride, the active ingredient in Imodium, treats acute and chronic diarrhea by slowing fecal movement through the intestinal tract, reducing the amount of feces and limiting fluid loss.