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
Colon (punctuation) address colons (and one optional double colon) separate up to 8 groups of 16 bits in hexadecimal representation. In a URL a colon follows the initial scheme name (such as HTTP and FTP), and separates a port number from the hostname or IP address. In BASIC, it is used as a separator between the statements or instructions in a single line, which is represented in other languages via the semicolon. In Forth, a colon "precedes" definition of a new word. Haskell uses a colon (pronounced as "cons", short for "construct") as an operator to add an element to the front