Britannica Sources used in this answer

How have bismuth salts been used during X-ray examinations of the alimentary tract?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A labeled periodic table element box for bismuth shows atomic number 83, symbol Bi, atomic weight 208.9804, electron configuration, and properties including solid state, rhombohedral crystal structure, and weakly acidic oxides. — bismuth Properties of bismuth.

Bismuth salts have been utilized in medical imaging as a contrast medium to outline the alimentary tract during X-ray examinations. In this application, the substance is used to improve the visibility of the digestive system on X-ray film by providing a sharp contrast against surrounding tissues.12

While bismuth salts have historically served this purpose, it is important to note that barium sulfate is currently the most extensively used opaque medium for examining the esophagus, stomach, rectum, and colon. Bismuth is sometimes administered for these diagnostic procedures in the form of finely divided metal or as suspensions of its insoluble salts.231