Used in pharmaceuticals as an active ingredient in gastrointestinal medications, particularly for treating peptic ulcers and gastritis. It has antimicrobial properties that help combat Helicobacter pylori, a bacterium linked to stomach ulcers. Forms a protective layer over ulcer sites, shielding them from acid and promoting healing. Also used in some radiopaque contrast agents due to bismuth's high density, aiding in imaging of the digestive tract. Found in certain antimicrobial and antidiarrheal formulations, especially in regions where resistance to conventional therapies is a concern.