Upper gastrointestinal series tract in addition to barium, and this procedure is called double-contrast imaging. In this case the gas is referred to as the negative contrast medium. Traditionally the images produced with barium contrast are made with plain-film radiography, but computed tomography is also used in combination with barium contrast, in which case the procedure is called CT enterography. Various types of barium X-ray examinations are used to examine different parts of the gastrointestinal tract. These include barium swallow, barium meal, barium follow-through, and barium enema. The barium swallow, barium meal, and barium follow-through are together also called an upper gastrointestinal series
Lower anterior resection Lower anterior resection A lower anterior resection, formally known as anterior resection of the rectum and colon and anterior excision of the rectum or simply anterior resection (less precise), is a common surgery for rectal cancer and occasionally is performed to remove a diseased or ruptured portion of the intestine in cases of diverticulitis. It is commonly abbreviated as LAR. LARs are for cancer in the proximal (upper) two-thirds of the rectum which lends itself well to resection while leaving the rectal sphincter intact. LARs, generally, give a better quality of life than abdominoperineal resections (APRs). Thus, LARs are generally