Gastrografin® is a water-soluble iodinated radiopaque contrast agent for x-ray examinations of the esophagus, stomach, proximal small intestine, colon and is also used for bowel visualization in abdominal computer tomograms.
The high opacification and delineation after oral or rectal administration is caused by a low absorption of the intact gastrointestinal tract. However, visualization of the distal small bowel is generally unsatisfactory, since the hypertonicity of the medium causes intraluminal diffusion of water with subsequent dilution.