Barium swallow test is done to test pharynx, oesophagus, and proximal stomach for any defects or problems. In this case, barium sulphate is used as a contrast which is mixed with water and given to the patients and it looks like a milkshake. In a barium enema, the barium sulphate solution is introduced as an enema through a tube inserted into the rectum. It is done to study the problems affecting the large bowel. A special type of X-ray machine called as the fluoroscope is used, which projects images on a video screen. It is used in diagnosing hiatal hernia, blockages, inflammation, tumours and other such problems in the digestive system.