What Are the Best Over-the-Counter Anti-Diarrhea Medicines?

Any time you experience diarrhea — whether caused by a virus or food allergy — you want relief fast.

The good news is that most cases of diarrhea can be treated with over-the-counter (OTC) medications found at your local pharmacy. But when the shelves are lined with many options, you might be left wondering which one is best for you. Let’s review.

What causes diarrhea?

If you have three or more loose, watery bowel movements in one day, it’s considered diarrhea. The most common causes of diarrhea are:

• Viruses, like norovirus or rotavirus

• Bacteria or parasites (tiny organisms) from contaminated food or water

• Some medications 

• Food allergies or intolerances, like lactose or gluten

• Medical conditions like irritable bowel syndrome (IBS)

Fortunately, most diarrhea goes away on its own within a day or two. But OTC diarrhea medicines can be helpful until then.

What OTC diarrhea medicines can I take?

There are a few OTC diarrhea medications available. They come in different dosage forms and have generic versions available. The products discussed here are some of the most well-known OTC diarrhea medications.

1. Imodium A-D

Imodium A-D (loperamide) is an anti-diarrheal medication. It works by slowing down your intestines, which means fewer trips to the bathroom. And it might shorten your bout of diarrhea by about a day.

Imodium A-D comes as a tablet, capsule, and liquid. Adults and children ages 12 years and older typically take the same dose. You should check with a healthcare provider or pharmacist for the proper dose if your child is under 12.

Pay close attention to the maximum daily dose on the package. Taking more Imodium A-D than recommended can lead to serious side effects (more on that later).

Below are the standard directions for Imodium A-D:

Medication image	Medication name and strength	Directions	Maximum dose
	Imodium A-D tablets or capsules (2 mg each)	Take 2 pills after the first loose stool. Then take 1 pill after each loose stool that follows.	Don’t take more than 4 tablets (8 mg) in 24 hours.
	Imodium A-D solution (1 mg/7.5 mL)	Take 30 mL after the first loose stool. Then take 15 mL after each loose stool that follows.	Don’t take more than 60 mL in 24 hours.

There’s also a version of Imodium A-D that combines loperamide with the gas relief medication simethicone. This product, called Imodium Multi-Symptom Relief, may help provide additional symptom relief. You may find it helpful if you’re experiencing both diarrhea and uncomfortable gas.

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2. Pepto-Bismol

Pepto-Bismol (bismuth subsalicylate) is used to treat diarrhea, upset stomach, and heartburn. It works by lessening inflammation (swelling) in the intestines. It also lowers the amount of fluid that enters your bowel. Pepto-Bismol may also help kill the organisms that are causing your diarrhea.

You can easily recognize Pepto-Bismol on pharmacy shelves by its familiar pink packaging. It’s most well known as a liquid. But it also comes as a capsule, tablet, and chewable tablet. It can be used for adults and children 12 years of age and older. For children under 12, ask your child’s healthcare provider before using it.

The standard directions for Pepto-Bismol are listed below:

Medication image	Medication name and strength	Directions	Maximum dose
	Pepto-Bismol capsules, tablets, or chewable tablets (262 mg each)	Take 2 pills every 30 minutes as needed. OR take 4 pills every hour as needed.	Don’t take more than 16 pills in 24 hours.
	Pepto-Bismol suspension (525 mg/30mL)	Take 30 mL every 30 minutes as needed. OR take 60 mL every hour as needed.	Don’t take more than 240 mL (8 fluid ounces) in 24 hours.

3. Kaopectate

Kaopectate (bismuth subsalicylate) is another popular choice to treat diarrhea for adults and children 12 years and older. It contains the same active ingredient as Pepto-Bismol. But there are a few differences between these two OTC diarrhea medicines.

Kaopectate comes as caplets and a liquid. The liquid offers more flavor options than Pepto-Bismol, like peppermint and vanilla.

The Kaopectate liquid also comes in two different strengths: a regular strength and a max strength. Read the package instructions carefully. The max strength contains double the amount of medication per dose.

Here are the standard directions for Kaopectate:

Medication image	Medication name and strength	Directions	Maximum dose
	Kaopectate caplets (262 mg each)	Take 2 caplets every 30 to 60 minutes as needed.	Don’t take more than 16 caplets in 24 hours.
	Kaopectate suspension (262 mg/15mL)	Take 30 mL every 30 minutes to 60 minutes as needed.	Don’t take more than 240 mL (8 fluid ounces) in 24 hours.
	Kaopectate MAX suspension (525 mg/15mL)	Take 30 mL every 60 minutes as needed.	Don’t take more than 120 mL (4 fluid ounces) in 24 hours.

4. Probiotics

Probiotics are tiny living organisms that can be found in dietary supplements and some fermented foods, like yogurt. Probiotic products contain “good bacteria'' that are similar to those naturally living in our digestive tracts. Experts think probiotics may help digest food, make vitamins, and support the immune system.

But can taking probiotics help treat diarrhea? Maybe. A review of 63 studies involving about 8,000 people found that probiotics helped diarrhea resolve about 1 day faster. But many different types of probiotics were used in these studies. Because of this, it’s unclear which type of probiotics might be the best for diarrhea. It’s best to ask your healthcare provider for recommendations if you’re considering taking probiotics for diarrhea.

Can I use these OTC medications for my child’s diarrhea?

It depends. In general, children ages 12 years and older can take the same dose of anti-diarrheal medications as adults. But some medications, especially those with bismuth subsalicylate, can be dangerous for babies and children. Talk with your child’s healthcare provider before giving them OTC diarrhea medicine. If OTC medications are recommended for your child’s diarrhea, the dose will likely be different.

What side effects can I expect from OTC diarrhea medicine?

OTC diarrhea medicines are generally well-tolerated when taken at recommended doses. Always follow the package instructions. Taking extra medication can make these side effects more likely.

Imodium A-D

Imodium A-D side effects at typical doses are mild and include dizziness, drowsiness, and tiredness. But taking more than recommended can cause dangerous changes in your heart rhythm. Ask your healthcare provider before taking Imodium A-D if you have an irregular heartbeat or take medications for your heart rate or rhythm.

Bismuth subsalicylate

A common side effect of Pepto-Bismol and Kaopectate is that they can darken your stools and tongue. This side effect is harmless and should go away within a few days of stopping the medication. Ringing in your ears (tinnitus) is also a temporary side effect you might experience.

Probiotics 

Probiotics are usually well-tolerated with very few side effects. But ask your healthcare provider about using probiotics if you have a weakened immune system. There’s a possibility that probiotics could cause infections if your immune system is very weak.

Is one OTC diarrhea medicine better than the others?

Studies comparing OTC diarrhea medicines are limited and dated. So it’s unclear if one option is better than others.

You should avoid Imodium A-D if you see any blood in your stool. This medication can worsen certain types of diarrhea, like inflammatory diarrhea. Contact your healthcare provider for next steps if you have bloody stools.

When should I see a healthcare provider for diarrhea?

Taking OTC diarrhea medicine isn’t always a good idea. Check in with a healthcare provider if you have any of these symptoms:

• Diarrhea that lasts longer than 2 days

• Fever of 102°F or higher

• Severe stomach or rectal pain

• Blood or pus in your stool

• Black stools

• Symptoms of dehydration

Why trust our experts?

Written by:

Tegan Smedley, PharmD, APh

Tegan Smedley, PharmD, APh, has 10 years of experience as a pharmacist. She has worked in a variety of settings, including retail, hospital, and ambulatory care.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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