What does barium do when used for the gastrointestinal tract?

Barium acts as a radiopaque contrast agent when used in diagnostic procedures of the gastrointestinal tract, such as barium X-rays and swallow examinations. It appears white on X-rays, allowing better visualization of the digestive organs and helping to identify any abnormalities. Barium is typically consumed orally or rectally to coat the gastrointestinal lining, making it more visible under X-ray imaging.