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
Colon classification facets are generally associated with every item in a library, and so form a reasonably universal sorting system. As an example, the subject "research in the cure of tuberculosis of lungs by x-ray conducted in India in 1950" would be categorized as: This is summarized in a specific call number: The colon classification uses 42 main classes that are combined with other letters, numbers and marks in a manner resembling the Library of Congress Classification to sort a publication. CC uses five primary categories, or facets, to further specify the sorting of a publication. Collectively, they are called "PMEST": The