A Barium Meal test (also part of an Upper GI Series) uses a chalky barium liquid, often with fizzy granules, to coat the esophagus, stomach, and duodenum so doctors can see them clearly on X-rays (fluoroscopy) to diagnose swallowing issues, pain, reflux, or ulcers, showing the shape, lining, and function of your upper digestive tract. It involves drinking the liquid and sometimes gas-producing agents, then tilting on an X-ray table while images are taken, and it’s generally safe but may cause constipation