For the evaluation of the level and cause of small bowel obstruction, an oral barium study is usually chosen. When perforation is whether barium or a water-soluble contrast agent should be used, because barium causes foreign body reactions as well as adhesions in the extraluminal tissues. Water-soluble contrast agent, on the other hand, are less satisfactory but in general have no untoward effects in the extraluminal tissues. Because of hyperosomolartity, water-soluble contrast will likely avoid pulmonary complications due to aspiration. The author performed this experimental study to compare the radiological efficacy of different contrast media in enteric follow-through examinations of obstructed small bowel. Rate had a ligature applied to the distal ileum via loparotomy. Four contrast media were subjected to testing by instillation via oro-gastric tube immediately after laparotomy. Radiographs were exposed at 1,4,and 8 hours and evaluated later. After 24 hours the animals were sacrificed and the stomach and small bowels, free from mesentery and omental tissue, were weighted with contrasts. The progression in the owel was proportionate to the osmolarity of the contrast media. After 1 hour, the observations indicated sodium diatrizoate(Gastrografin, Schering) to be the least favorable medium with respect to sharpness of the mucosal border. After 8 hours, barium gave a poorer delineation compared to Ioxaglate(Hexabric, Guerbet) and Iopromide(Ultravist, Schering). Early deaths were noted in the sodium diatrizoate and ioxaglate groups. So we conclude that when using a rather high-volume bolus, low-osmolar non-ionic contrast media seem to have significant prospects for general diagnostic use in patients with suspected intestinal obstruction.