Abdominal x-ray as a scout film for other procedures such as barium enemas. An upper gastrointestinal series is where a contrast medium, usually a radiocontrast agent such as barium sulfate barium salt mixed with water, is ingested or instilled into the gastrointestinal tract, and X-rays are used to create radiographs of the regions of interest. The barium enhances the visibility of the relevant parts of the gastrointestinal tract by coating the inside wall of the tract and appearing white on the film. A lower gastrointestinal series is where radiographs are taken while barium sulfate, a radiocontrast agent, fills the colon via an
Gastrointestinal bleeding risk about fourfold. SSRIs, corticosteroids, and anticoagulants may also increase the risk. The risk with dabigatran is 30% greater than that with warfarin. Lower gastrointestinal bleeding is typically from the colon, rectum or anus. Common causes of lower gastrointestinal bleeding include hemorrhoids, cancer, angiodysplasia, ulcerative colitis, Crohn's disease, and aortoenteric fistula. It may be indicated by the passage of fresh red blood rectally, especially in the absence of bloody vomiting. Isolated melena may originate from anywhere between the stomach and the proximal colon. A number of foods and medications can turn the stool either red or black. Bismuth found in