What Does Pepto-Bismol Do? Find Relief and Avoid Side Effects

How to take Pepto-Bismol safely to relieve stomach upset and diarrhea

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Pepto-Bismol (bismuth subsalicylate) is an over-the-counter treatment for diarrhea, upset stomach, and nausea. Sometimes referred to as "the pink stuff," Pepto-Bismol is safe and effective for short-term use.

Side effects of Pepto-Bismol are generally mild and can include a black tongue, black stool, and constipation. More serious side effects can occur but are rare. This article discusses Pepto-Bismol, how it works, and potential side effects.

Safety Tips for Taking Pepto-Bismol
Verywell / Brianna Gilmartin

Uses

Pepto-Bismol is primarily used for the short-term treatment of the following digestive symptoms in adults and children aged 12 and older:

  • Diarrhea
  • Nausea
  • Stomach upset
  • Indigestion
  • Heartburn
  • Excessive intestinal gas
  • Excessive burping
  • A feeling of fullness caused by eating too much
  • Discomfort from drinking too much alcohol

Interestingly, researchers have found that when Pepto-Bismol is combined with antibiotics, it can be quite effective in treating Helicobacter pylori, an infection that has been linked to peptic ulcers and gastritis.

How Pepto-Bismol Works

The scientific name for the active ingredient in Pepto-Bismol is bismuth subsalicylate. Bismuth is a mineral that has antibacterial, antacid, and antidiarrheal effects. Subsalicylate is a medication in the same class as aspirin.

The active ingredients of Pepto-Bismol are thought to have the following actions within the body:

  • Increasing the amount of fluid that is absorbed in the intestines, therefore firming up stool
  • Reducing inflammation
  • Calming intestinal spasms
  • Reducing the population of disease-causing bacteria and/or viruses
  • Reducing excess levels of stomach acid

Side Effects

Pepto-Bismol is considered quite safe for short-term use by adults and children aged 12 or over.

Common Side Effects

When used properly, Pepto-Bismol has a few side effects:

These side effects are temporary and generally harmless.

Serious Side Effects

Serious side effects of Pepto-Bismol are rare but not unheard of.

Adults over the age of 65: The side effect of constipation may lead to a bowel blockage, a serious condition.

Children and teens: Pepto-Bismol is in the aspirin family. Aspirin use in children and teenagers is associated with a risk of Reye's syndrome, a potentially life-threatening illness. This risk is particularly high for those who have chickenpox, influenza (the flu), or any other type of viral infection.​

Pepto Kids, a formulation made for children, does not contain bismuth subsalicylate and is safe for children. Pepto Kids is designed to treat heartburn and upset stomach in children.

When To Call Your Healthcare Provider

Contact your healthcare provider immediately and stop taking Pepto-Bismol if you experience:

  • Ringing in the ears
  • Diarrhea that lasts for more than two days
  • Severe vomiting
  • High fever
  • Any signs of an allergic reaction

If you think you have taken an overdose or are experiencing any severe symptoms, seek immediate attention by calling an ambulance.

Before Taking

Pepto-Bismol is only recommended for use for a two-day period. That, therefore, makes it a poor choice as a treatment for people who experience chronic diarrhea, common in those with IBS. It also makes it a poor choice for people who experience chronic heartburn or acid reflux from gastroesophageal reflux disease (GERD).

Before taking Pepto-Bismol, it is essential that you clear it with your healthcare provider, as the medication may interact with other medications that you are taking, particularly some medications for diabetes or gout, blood thinners, and certain antibiotics.

Precautions and Contraindications

Pepto-Bismol should not be taken by anyone who:

  • Is younger than 12 years of age
  • Has the flu
  • Has a fever and signs of blood in the stool
  • Has chickenpox or has received the chickenpox vaccination within the past six weeks
  • Is pregnant
  • Is breastfeeding
  • Is allergic to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs)

Dosage

Pepto-Bismol is an oral medication that comes in liquid, tablet, or chewable form. Follow the directions and dosing recommendations on the product packaging carefully.

You do not need to take the medication with food. Do not take Pepto-Bismol for more than two days. Be sure to drink plenty of water while taking Pepto-Bismol to replace fluid lost from diarrhea episodes.

A Word From Verywell

Although it may be tempting to take Pepto-Bismol to address irritable bowel symptoms, remember that it is only recommended for a maximum of two days. Thus, it is best only for short-term symptoms, and long-term use may enhance side effects. When you're experiencing chronic symptoms, work with your healthcare provider to find a better solution.

Frequently Asked Questions

  • What are the side effects of Pepto-Bismol?

    The most common side effect of Pepto-Bismol is a black tongue or black stools. Both are harmless. Pepto-Bismol contains a non-toxic metal called bismuth that, when mixed with sulfur (a naturally occurring mineral in the body), forms a black substance called bismuth sulfide.

  • Can Pepto-Bismol cause severe side effects?

    On rare occasions, Pepto-Bismol has been known to cause potentially serious side effects. Call your healthcare provider if you experience any of the following after taking Pepto-Bismol:

  • Who should not take Pepto-Bismol?

    Pepto-Bismol is contraindicated for use in people with the following conditions:

    Also, children under age 12 should not take regular Pepto-Bismol; children under 2 shouldn't be given Pepto Kids.

  • Is Pepto-Bismol safe during pregnancy?

    Pepto-Bismol contains bismuth subsalicylate, a drug that is generally avoided during the third trimester as it increases the risk of uterine bleeding. There remains considerable debate about the actual risk, but it may be best to avoid Pepto-Bismol just to be safe.

  • What drugs interact with Pepto-Bismol?

    Pepto-Bismol can potentially interact with a wide range of medications. Let your healthcare provider know if you take any of the following before starting Pepto-Bismol:

  • What are the alternatives to Pepto-Bismol?

    There are several over-the-counter alternatives to Pepto-Bismol based on the symptom being treated:

  • How long does it take Pepto-Bismol to work?

    Pepto-Bismol generally starts to work within 30 minutes to an hour. If you aren't feeling relief after an hour, you can take a second dose.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. National Library of Medicine. Label: Pepto-Bismol—bismuth subsalicylate kit.

  2. Graham DY, Lee SY. How to effectively use bismuth quadruple therapy: The good, the bad, and the ugly. Gastroenterol Clin North Am. 2015;44(3):537-63. doi:10.1016/j.gtc.2015.05.003

  3. Procter & Gamble. Pepto Bismol Original Liquid [package labeling].

  4. Budisak P, Abbas M. Bismuth subsalicylate. In: StatPearls [Internet].

  5. Servery J, Chang J. Over-the-counter medications in pregnancy. Am Fam Physician. 2014 Oct 15;90(8):548-55.

  6. MedlinePlus. Bismuth subsalicylate.

By Barbara Bolen, PhD
Barbara Bolen, PhD, is a licensed clinical psychologist and health coach. She has written multiple books focused on living with irritable bowel syndrome.