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 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