Pepto-Bismol contains the active ingredient bismuth subsalicylate, a substance that coats the gastrointestinal tract, reduces inflammation and kills bacteria such as E. coli, according to NetDoctor. Scientists are unsure how this process works. Pepto-Bismol also reduces irritation and pain by decreasing secretions in the digestive tract.
Pepto-Bismol chewable tablets and liquid suspension help ease the symptoms of nausea, heartburn, indigestion and diarrhea. Dugs.com explains the medicine also limits the stomach's reaction when people overeat or drink too much. Pepto-Bismol makes stools firmer and decreases bowel movements in the large intestines. Doctors may instruct patients to use this drug to treat other conditions.
WebMD states this product should not be used to treat diarrhea if the digestive condition occurs along with fever or bloody stool. Patients should not take Pepto-Bismol for chronic ulcers unless instructed by a doctor, but it may be used along with other medications to treat ulcers that are caused by a bacterial infection of Helicobacter pylori. Salicylates may cause bleeding problems in ulcers.
NetDoctor explains that Pepto-Bismol tablets and suspension can be taken with or without food, and more than eight doses should not be consumed in a 24-hour period. Doses can be repeated every 30 to 60 minutes as needed. The liquid suspension should be shaken before measuring, and tablets should be chewed well before swallowing.