“…A variety of methods have been advocated including encouraging the patient to swallow air spontaneously [3], placing a needle hole in the drinking straw [4], passing a nasogastric tube, administrating carbonated or "bubbly" barium [5,6], and preceding the barium by a carbonated solution such as tonic water. Most widely used, however, are a variety of effervescent agents in the form of powders, granules, or tablets [7][8][9][10][11][12][13]. Unfortunately, many of these effervescent agents are not currently marketed in the United States.…”