Altogether 100 patients with 117 episodes of ASBO were randomized into control and gastrografin groups in a double blinded fashion. Eight episodes in eight patients were excluded due to protocol violation. In Gastrografin group,100 ml of the dye administered through a nasogastric tube and complete obstruction has been considered if the contrast failed to reach the colon on the 24-hour film. Patients were operated on only if they developed signs of strangulation or failed to improve within 48 hours.