Bismuth subsalicylate, sold under the brand name Pepto-Bismol, is a medication used to treat temporary discomforts of the stomach and gastrointestinal tract, such as diarrhea, indigestion, heartburn and nausea.ommonly known as pink bismuth, it is also sometimes the active ingredient in Kaopectate. It has the empirical chemical formula of C 7 H 5 BiO 4, is a colloidal substance obtained by hydrolysis of bismuth salicylate (Bi{C 6 H 4 (OH)CO 2 } 3).