Bismuth subsalicylate is an antacid and antidiarrheal medication that is used to treat indigestion, upset stomach, and diarrhea. It works by reducing inflammation in the stomach and intestines, and by killing certain bacteria that can cause diarrhea. It is available in tablet and liquid form, and is sold under various brand names such as Pepto-Bismol. Bismuth subsalicylate should be taken as directed by a healthcare professional, and patients should follow the recommended dosing instructions on the label. It is important to inform your doctor if you have any allergies, medical conditions, or are taking any other medications before taking bismuth subsalicylate.