Friday, May 24, 2024
HomeDiscoverHow It WorksHow does Pepto-Bismol work?

How does Pepto-Bismol work?

Pepto-Bismol is an over-the-counter medicine used to treat diarrhea and upset stomach – how does it work and how long does it take?

Pepto-Bismol is a commonly used medication to help alleviate symptoms of an upset stomach, diarrhea, nausea, heartburn, and indigestion. It is an over-the-counter medication and does not require a prescription from a doctor.

Pepto-Bismol is considered an effective option that works to treat mild symptoms of diarrhea and upset stomach.

How does Pepto-Bismol work?

Pepto-Bismol includes the active ingredient bismuth subsalicylate. Bismuth exhibits anti-bacterial, anti-diarrheal, and anti-inflammation properties.

Pepto-Bismol works by coating the walls of the gastrointestinal tract, forming protection against stomach acid.

Reducing symptoms

It can act as an antacid, which can help in reducing the symptoms associated with an upset stomach, heartburn, and indigestion.

The drug can treat diarrhea by stimulating the absorption of fluids and electrolytes (sodium and chloride), leading to a decrease in fluid loss. It inhibits the formation of prostaglandins, which helps reduce inflammation and excessive movement in the digestive tract. 

It also hinders intestinal secretions caused by E. coli and binds toxins to kill the infectious bacteria.

Pepto-Bismol is taken orally through the mouth. Upon entering the stomach, bismuth subsalicylate hydrolyzes into bismuth and salicylic acid.

The salicylic acid is completely absorbed into the blood in the small intestine, while the bismuth compound produces bismuth salts.

The bismuth salts help inhibit the growth and binding of the bacteria on the gastrointestinal wall.

This enables the drug to get rid of H. pylori as well as heal any ulcers. 

Pepto-Bismol is available in two forms

Pepto-Bismol is available in two forms: oral suspension (liquid) and tablets, which can be either chewable or non-chewable. The chewable tablets generally dissolve in the mouth so they can be either chewed or swallowed.

The tablets cannot be chewed and must be swallowed whole with water.

Patients should take the medication as directed by their doctor or pharmacist. The dosage usually depends on the individual’s age and medical condition.

How long does Pepto-Bismol take to work?

People taking Pepto-Bismol can generally expect it to start working within 30 to 60 minutes.

They can repeat their dose after around 30 minutes and it is recommended to take up to eight doses in one day.

What is Pepto-Bismol used for?

This medication has been used to treat and prevent traveler’s diarrhea, a condition affecting approximately 20 and 50 percent of tourists visiting developing countries.

Traveler’s diarrhea is most commonly caused by bacteria such as Escherichia coli (E. coli), generally found in contaminated food and water.

A 2003 study, published in the International Journal of Antimicrobial Agents, suggests that the medication was less effective in preventing traveler’s diarrhea in comparison to antibiotics.

Upon medical advice of a doctor, Pepto-Bismol can be used to treat peptic or duodenal ulcer disease, caused by bacterial infections such as Helicobacter pylori (H. pylori) in the digestive tract.

According to several studies, this drug, prescribed along with other medications such as a proton pump inhibitor as part of a quadruple treatment regimen, has been able to get rid of around ninety percent of H. pylori in the digestive tract.

Risks and Side Effects of Taking Pepto-Bismol                                          

Patients are generally recommended to take Pepto-Bismol for up to two days.

This is because the medication can increase their risk of side effects if taken for more than two days.

A common side effect of Pepto-Bismol is dark or black tongue and stools. This side effect is temporary until the individual has stopped taking the drug.

Other side effects associated

Other side effects associated with the medication include constipation, diarrhea, ringing in the ears, nausea, anxiety, and muscle spasms.

These side effects are considered to be serious and individuals experiencing them will need to immediately contact their doctor to seek medical attention.

For what type of patients is this drug not recommended?

The drug is not recommended for patients with medical conditions, which include bleeding disorders such as hemophilia, active gastrointestinal ulcers, gout, or diabetes.

They will need to consult a doctor before deciding to take Pepto-Bismol.

Persons taking medications with high levels of salicylate or anticoagulants (blood thinners) are recommended not to take Pepto-Bismol.

People found to be sensitive to aspirin are recommended to avoid taking Pepto-Bismol or any other medications containing bismuth subsalicylate.

This is because they can be intolerant to salicylate and potentially develop an allergic reaction to the drug.

Pepto-Bismol while Pregnant or Breastfeeding

Women who are pregnant or breastfeeding, are recommended to talk to their doctor before deciding to take Pepto-Bismol.

The drug is generally not recommended for women during pregnancy. This may be due to the risk of absorbing salicylate, which can cross the placenta.

It is not prescribed to pregnant women in their second and third trimesters as it is possibly linked to the increased risk of bleeding during delivery. 

According to the Center for Disease Control and Prevention (CDC) and some research studies, it is recommended that women who are breastfeeding should not take the drug as it can potentially pass into breast milk.

However, more research may be needed to assess the safety of using Pepto-Bismol during pregnancy or breastfeeding.

Pepto-Bismol for Children

Parents with children under the age of twelve are recommended to consult their doctor before deciding to use Pepto-Bismol for their child.

There is a form of the drug (chewable tablets) available for children in which the manufacturers have replaced bismuth salicylate with another active ingredient, calcium carbonate.

It is recommended that children under the age of two years do not use the drug in any form, because of the risks of accumulating bismuth, magnesium, or aluminum.

Children or adolescents who have been recovering from viral infections such as chicken pox or the flu are recommended not to use Pepto-Bismol.

This is because the drug can potentially increase the risk of developing Reye’s syndrome, a progressive brain disorder that leads to swelling in the brain and the liver.


  1. Budisak P, Abbas M. Bismuth Subsalicylate. [Updated 2020 Jul 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:
  2. Ericsson CD. Travellers’ diarrhoea. Int J Antimicrob Agents. 2003;21(2):116-124. doi:10.1016/s0924-8579(02)00282-0
  3. de Boer WA, Tytgat GN. Regular review: treatment of Helicobacter pylori infection. BMJ. 2000;320(7226):31-34. doi:10.1136/bmj.320.7226.31
  4. Testerman TL, Morris J. Beyond the stomach: an updated view of Helicobacter pylori pathogenesis, diagnosis, and treatment. World J Gastroenterol. 2014;20(36):12781-12808. doi:10.3748/wjg.v20.i36.12781
  5. Thazhath SS, Haque M, Florin TH. Oral bismuth for chronic intractable diarrheal conditions? Clin Exp Gastroenterol. 2013;6:19-25. doi:10.2147/CEG.S41743
  6. Gorbach SL. Bismuth therapy in gastrointestinal diseases. Gastroenterology. 1990;99(3):863-875. doi:10.1016/0016-5085(90)90983-8
  7. Pepto-Bismol. Retrieved from,8%20doses%20in%2024%20hours.
  8. Black RA, Hill DA. Over-the-counter medications in pregnancy. Am Fam Physician. 2003;67(12):2517-2524.
  9. Is It Safe to Use Pepto-Bismol During Pregnancy or Breastfeeding? Retrieved from
  10. Can You Have Pepto Bismol When Breastfeeding? Retrieved from
  11. Is Pepto-Bismol safe for kids? Retrieved from’s%20Pepto%20Antacid%20is%20available,in%20children%20under%20age%2012.


Please enter your comment!
Please enter your name here

Latest News and Articles


Stay Connected

Article of the month

Recognizing HIE: A Call for Advocacy

Have you heard of HIE? It’s the second leading cause of infant mortality and lifelong disability worldwide. 2-3 per 1,000 live births in high-income...

Joke Of The Day – May 24

A scientist tells a pharmacist, “Give me some prepared tablets of acetylsalicylic acid.” “Do you mean aspirin?” asks the pharmacist. The scientist slaps his forehead. “That’s...


error: Content is read-only and copy-protected.