It's best to pick one instead of taking both: neither the Pepto-Bismol nor the Imodium label tells you to use the other alongside it, and the CDC lists them as alternatives for mild diarrhea, not a combination. The NHS says to tell a pharmacist before taking loperamide (Imodium) with other medicines for diarrhea. If 1 product isn't working after 2 days, both labels say to stop and ask a doctor, not to add a second product. Skip both and get checked if you have bloody or black stool.
What do the labels say about using both?
Neither Drug Facts label has a line about the other product. That is not the same as saying the pair is safe. The CDC's travelers' diarrhea guidance says to consider bismuth subsalicylate or loperamide for mild diarrhea, offering them as 2 options rather than a combination.
The NHS loperamide page asks you to tell a doctor or pharmacist if you take other medicines for diarrhea, constipation, or other stomach and bowel problems. So if you have already taken one and are thinking about the other, ask a pharmacist first.
The 2 drugs work differently. MedlinePlus says loperamide cuts the flow of fluid into the bowel and slows bowel movements. The CDC lists constipation as a possible side effect of bismuth subsalicylate. No source we found tests the 2 taken together, but stacking 2 products that can each slow things down may leave you more blocked up than you need to be.
- Pepto-Bismol (bismuth subsalicylate): stop and ask a doctor if diarrhea lasts more than 2 days. Original liquid: no more than 8 doses (240 mL) in 24 hours.
- Imodium A-D (loperamide 2 mg): stop and ask a doctor if diarrhea lasts more than 2 days. Adults and kids 12 and up: no more than 4 caplets in 24 hours.
- Imodium heart alert: the label warns that taking more than directed can cause serious heart problems or death.
How do I pick between Pepto and Imodium?
Both are labeled for diarrhea, including travelers' diarrhea. The differences that matter are about you, not the diarrhea.
- Pepto-Bismol also covers upset stomach: its label lists heartburn, indigestion, nausea, gas, and fullness from overeating or drinking. Imodium is only for diarrhea.
- Skip Pepto if salicylates are a problem: it contains a salicylate. Don't use it if you're allergic to aspirin or other salicylates, take other salicylate products, or have an ulcer or a bleeding problem.
- Ask first about Pepto if you take medicine to thin your blood, or medicine for diabetes, gout, or arthritis. The label says to check with a doctor or pharmacist before use.
- Ask first about Imodium if you have liver disease, a history of abnormal heart rhythm, or take any prescription drug, since loperamide can interact with some of them.
- Imodium can make you drowsy or dizzy: the label says to be careful driving.
When should you not try to stop diarrhea at all?
Sometimes diarrhea is your body clearing an infection, and slowing it down can make things worse. Both labels say not to use the product if you have bloody or black stool. Both say to ask a doctor first if you have a fever or mucus in your stool.
The CDC says anti-motility drugs like loperamide alone are not recommended for bloody diarrhea or for diarrhea with fever. The NHS says not to take loperamide for severe diarrhea after a course of antibiotics, during a flare of ulcerative colitis or another inflammatory bowel condition, or if your belly looks swollen.
- Bloody or black stool
- Fever, or mucus in your stool
- Severe diarrhea after taking antibiotics
- A swollen or bulging belly
Is dehydration the bigger worry?
Often, yes. Both labels tell you to drink plenty of clear fluids to help prevent dehydration, whichever one you take. The NHS suggests small sips if you feel sick, and says a pharmacist can recommend oral rehydration powder.
Watch for dark, strong-smelling pee or peeing less than usual. If those signs don't improve after oral rehydration drinks, or you keep being sick and can't keep fluids down, get seen.
When should you get care?
In an emergency, call 911Get care the same day for bloody or black stool, a fever with diarrhea, diarrhea lasting more than 2 days on either medicine, a swollen or bulging belly, ringing in your ears or hearing loss after Pepto-Bismol, or signs of dehydration that don't improve with fluids.
Get care the same day if you keep being sick and can't keep fluids down, or if a child under 5 shows signs of dehydration such as fewer wet diapers.
Call 911 for a fast, pounding, or irregular heartbeat, fainting, or slow, shallow breathing after Imodium, especially if more than the label dose was taken.
Call 911 for vomit with blood or that looks like coffee grounds, sudden severe belly pain, blue or gray lips or skin, severe trouble breathing, or confusion or not responding as usual.
If someone took too much of either medicine, call Poison Control at 1-800-222-1222.
How our AI doctor decides when to send you to care ›Can kids and teens take Pepto or Imodium?
Pepto-Bismol's label says children and teenagers who have or are recovering from chickenpox or flu-like symptoms should not use it, because of Reye's syndrome, a rare but serious illness. If behavior changes happen along with nausea and vomiting, the label says to contact a doctor, since these can be early signs of Reye's. For children under 12, the label says ask a doctor.
Imodium A-D caplets are labeled for ages 6 and up with weight-based doses, ask a doctor for ages 2 to 5, and do not use under age 2. MedlinePlus also says loperamide should not be given to a child under 2. The NHS goes further and says children 11 and under should only take loperamide if a doctor prescribes it. Because the US label and the NHS differ, check with your child's doctor or a pharmacist before giving it.
Common questions
Can I take Pepto-Bismol and Imodium together?
It's better to pick one. Neither label tells you to use them together, and the CDC lists them as alternatives. The NHS says to tell a pharmacist before taking loperamide with other diarrhea medicines.
I took Pepto and it didn't work. Can I switch to Imodium?
Ask a pharmacist first, since they can check timing and your other medicines. If diarrhea has already lasted more than 2 days, both labels say to stop and ask a doctor rather than try another product.
Why did my stool turn black after Pepto-Bismol?
Bismuth can cause a temporary, harmless darkening of the stool and tongue. The CDC says this is common. Black stool before you took Pepto, or black stool that doesn't go away after you stop, needs checking because it can be a sign of bleeding.
Can I take Imodium with a fever?
The label says to ask a doctor before using it if you have a fever. The CDC says anti-motility drugs alone are not recommended for diarrhea with fever.
Can my teenager take Pepto-Bismol?
The label gives doses for ages 12 and up, but teens who have or are recovering from chickenpox or flu-like symptoms should not use it because of the risk of Reye's syndrome. If you're not sure what's causing their symptoms, ask a pharmacist or doctor first.
Pymander is not a replacement for a physician and does not provide medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with questions about a medical condition. If you think you may have a medical emergency, call 911.