Tums and Pepto-Bismol can safely be taken together as there is no interaction between the two medications. While Pepto-Bismol has weak antacid properties and may help with heartburn and indigestion, it is more effective for symptoms of diarrhea. Tums is generally works faster and more effectively as an antacid.


Pepto-Bismol (bismuth subsalicylate) is classified as an antidiarrheal agent. Not only is it effective for sporadic (i.e. acute) cases of diarrhea, it can be used prophylactically for travelers diarrhea as it has anti-infective properties. In addition to its beneficent effects for treating diarrhea, it is also used as an antacid and can treat peptic ulcer disease.

Pepto-Bismol has works via a variety of mechanisms and is thought to:

  • Influence prostaglandin synthesis
  • Work as an anti-infective agent (effective against both viruses and bacteria)
  • Decrease adherence of viral/bacetial infections to the gut wall
  • Decrease toxins released from bacteria
  • Have antacid properties

Due to the inconsistent way Pepto-Bismol is metabolized, as well as the fact that nearly no Bismuth is absorbed, continual dosing about 30 to 60 minutes apart is sometimes required for optimal effects.


Tums is simply calcium carbonate and is used to neutralize stomach acid (raise the pH of the stomach) quickly. While there are more effective long term acid blockers available over the counter (e.g. Pepcid and Prilosec), calcium carbonate products tend to work the fastest to relieve symptoms of heart burn and indigestion as they begin to work immediately after being ingested.

Tums are to be taken on an "as needed" basis and can be dosed anytime symptoms arise. However, long term use has been associated with "rebound acid reflex" and if your symptoms occur consistently and continually, you may need to try other therapy options.

Taking Pepto-Bismol With Tums

As mentioned above, Pepto-Bismol is safe to take with Tums.  There is no interaction between the two and they can be used together safely.