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 gastrointestinal bleeding as bleeding originating distal to the ileocecal valve which includes the colon, rectum, and anus. LGIB was previously defined as any bleed that occurs distal to the ligament of Treitz, which included the aforementioned parts of the intestine and also included the last 1/4 of the duodenum and the entire area of the jejunum and ileum. This has been divided into middle gastrointestinal bleeding (from the ligament of Treitz to the ileocecal valve) and lower gastrointestinal bleeding which involves a bleed anywhere from the ileocecal valve to the anus. The stool of a person with a lower gastrointestinal bleed is