Anti-diarrheal medicine: Imodium vs Pepto-Bismol, doses and limits
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- Imodium A-D caplets (loperamide 2 mg). Best for: Fast control of diarrhea symptoms. See options on Amazon
- Imodium Multi-Symptom Relief. Best for: Diarrhea with gas and cramping. See options on Amazon
- Pepto-Bismol liquid. Best for: Diarrhea plus upset stomach. See options on Amazon
Loperamide vs bismuth subsalicylate
| Detail | Imodium A-D (loperamide HCl 2 mg) | Pepto-Bismol liquid (bismuth subsalicylate 525 mg per 30 mL) |
|---|---|---|
| Uses | Controls symptoms of diarrhea, including travelers' diarrhea | Diarrhea, travelers' diarrhea, and upset stomach, heartburn, indigestion, nausea |
| Adult dose (12 and over) | 2 caplets after first loose stool, then 1 after each; max 4 in 24 hours | 30 mL every half hour or 60 mL every hour for diarrhea; max 8 doses (240 mL) in 24 hours |
| Key warning | More than directed can cause serious heart problems or death | Contains salicylate; Reye's syndrome warning for children and teens |
| Children | Doses by weight from 6 years; ask a doctor for 2 to 5; not under 2 | Under 12: ask a doctor |
Details are from the Imodium A-D and Pepto-Bismol DailyMed labels.
How to use loperamide
The Imodium A-D label says to drink plenty of clear fluids to help prevent dehydration caused by diarrhea, and to use weight to dose if possible, otherwise age:
- Adults and children 12 and over: 2 caplets after the first loose stool, 1 caplet after each later loose stool, no more than 4 caplets in 24 hours.
- Children 9 to 11 years (60 to 95 lbs): 1 caplet after the first loose stool, half a caplet after each later one, no more than 3 in 24 hours.
- Children 6 to 8 years (48 to 59 lbs): 1 caplet, then half a caplet, no more than 2 in 24 hours.
- Children 2 to 5 years: ask a doctor. Under 2: do not use.
Loperamide warnings
- Heart alert. Taking more than directed can cause serious heart problems or death.
- Do not use if you have bloody or black stool, or if you have ever had a rash or other allergic reaction to loperamide.
- Ask a doctor first if you have fever, mucus in the stool, a history of liver disease or a history of abnormal heart rhythm.
- Drug interactions. Ask a doctor or pharmacist if you take a prescription drug, since loperamide may interact with certain prescription drugs.
- Drowsiness. Tiredness, drowsiness or dizziness may occur; be careful driving.
Imodium Multi-Symptom Relief adds simethicone 125 mg for gas, bloating, pressure and cramps; see our simethicone gas relief guide.
Pepto-Bismol warnings
The Pepto-Bismol label says children and teenagers who have or are recovering from chicken pox or flu-like symptoms should not use it, because of Reye's syndrome, a rare but serious illness. It contains salicylate, so do not take it if you are allergic to salicylates, including aspirin, or take other salicylate products. Do not use it if you have an ulcer, a bleeding problem, or bloody or black stool.
Ask a doctor or pharmacist first if you take a blood thinner or medicine for diabetes, gout or arthritis. A temporary but harmless darkening of the stool or tongue may occur. Stop and ask a doctor if ringing in the ears or loss of hearing occurs.
Fluids come first
Both labels say to drink plenty of clear fluids to help prevent dehydration caused by diarrhea. Anti-diarrheals control symptoms, but replacing fluids is the priority, especially for children and older adults. For rehydration options, see our electrolyte drink powder guide. For gut health over the longer term, see our spore-based probiotic guide.
When to see a doctor
Stop use and ask a doctor if symptoms get worse, diarrhea lasts more than 2 days, or you get abdominal swelling or bulging, the Imodium label says. Do not use either product with bloody or black stool, and ask a doctor first if you have a fever or mucus in the stool. Get care quickly for signs of dehydration such as very little urine, dizziness or a dry mouth, especially in young children.
In case of overdose, get medical help or contact a Poison Control Center right away at 1-800-222-1222.
What to look for when you buy
Imodium A-D caplets (loperamide 2 mg)
Best for: Fast control of diarrhea symptoms
Its label lists loperamide HCl 2 mg for diarrhea, including travelers' diarrhea.
Watch out: Never take more than directed; max 4 caplets in 24 hours for adults.
See options on AmazonImodium Multi-Symptom Relief
Best for: Diarrhea with gas and cramping
Its label lists loperamide HCl 2 mg plus simethicone 125 mg.
Watch out: Do not use if you have difficulty swallowing.
See options on AmazonPepto-Bismol liquid
Best for: Diarrhea plus upset stomach
Its label lists bismuth subsalicylate 525 mg per 30 mL for diarrhea, heartburn, nausea and indigestion.
Watch out: Not for children or teens recovering from chickenpox or flu-like symptoms.
See options on AmazonQuestions people ask
- Is Imodium or Pepto-Bismol better for diarrhea?
- Imodium (loperamide) targets diarrhea; Pepto-Bismol also covers upset stomach, but contains salicylate.
- How much Imodium can I take?
- Adults: 2 caplets after the first loose stool, then 1 after each, no more than 4 in 24 hours.
- Is too much Imodium dangerous?
- Yes. The label says taking more than directed can cause serious heart problems or death.
- Can kids take anti-diarrheal medicine?
- Imodium lists weight-based doses from age 6; ask a doctor for ages 2 to 5 and do not use under 2.
- When should I stop and see a doctor?
- If diarrhea lasts more than 2 days, gets worse, or you have bloody or black stool.
Sources
- Imodium A-D (loperamide HCl) caplet label (dailymed.nlm.nih.gov), DailyMed, U.S. National Library of Medicine
- Imodium Multi-Symptom Relief (loperamide and simethicone) label (dailymed.nlm.nih.gov), DailyMed, U.S. National Library of Medicine
- Pepto-Bismol (bismuth subsalicylate) suspension label (dailymed.nlm.nih.gov), DailyMed, U.S. National Library of Medicine