“…The fluorescein string test, described originally by Traphagen and Karlan (1958), has received wide acceptance as a safe and accurate method for localizing the site of bleeding from the upper gastrointestinal tract Haynes, Pittman, and Christakis, 1960;Glaser and Charles, 1963;Pittman, 1964;Reisberg and Haubric, 1965;Nissenbaum, Attia, DiBianco, and Groisser, 1965). To perform this test, a radiopaque marked tape or tube is passed orally into the upper intestine and a radiograph of the upper abdomen is obtained to ascertain the position of the device.…”