Upper gastrointestinal series (or study), whereas the barium enema is called a lower gastrointestinal series (or study). In upper gastrointestinal series examinations, the barium sulfate is mixed with water and swallowed orally, whereas in the lower gastrointestinal series (barium enema), the barium contrast agent is administered as an enema through a small tube inserted into the rectum. Barium X-ray examinations are useful tools for the study of appearance and function of the parts of the gastrointestinal tract. They are used to diagnose and monitor esophageal reflux, dysphagia, hiatus hernia, strictures, diverticula, pyloric stenosis, gastritis, enteritis, volvulus, varices, ulcers, tumors, and gastrointestinal dysmotility, as
Lower gastrointestinal series colon to distend it and provide better images (often called a "double-contrast" exam). If air is used, the enema tube will be reinserted if it had been removed and a small amount of air will be introduced into the colon, and more X-ray pictures are taken. The patient is usually asked to move to different positions and the table is slightly tipped to get different views. If there is a suspected bowel perforation, a water-soluble contrast agent is used instead of barium. The procedure is otherwise very similar, although the images will be of poorer quality. If a perforation exists,