A barium swallow is a test that may be used to determine the disorder of the upper gastrointestinal (GI) tract, or the cause of painful swallowing, difficulty with swallowing, abdominal pain, bloodstained vomit, or unexplained weight loss. This test is done using Barium Sulfate mixture. Barium sulfate is a metallic compound that shows up on X-rays and is used to help see abnormalities in the esophagus and stomach. When taking the test, you drink a preparation containing this solution. The X-rays track its path through your digestive system. Although this test is safe, but barium swallow might have some complications.