AIM: To compare the diagnostic accuracy of a consolidated method (i.e.gastrografin) and a new one (i.e.radiopaque markers) in detecting complete intestinal obstruction. MATERIALS AND METHODS: Twenty-one patients with suspected small bowel obstruction were enrolled and received at admission orally 100 ml of Gastrografin and 10 radiopaque markers at the same time. A series of plain abdominal radiograms was taked and evaluated to decide whether the obstruction was complete or not. The results of radiological evaluations were not disclosed to the surgeons responsible for the patient’s treatment, therefore clinical decisions were assumed on clinical grounds only. RESULTS: In 16 out of the 21 enrolled patients both methods demonstrated only a partial obstruction; clinically none of them required surgery. Five patients showed complete bowel obstruction by the radiopaque markers method; out of those the gastrografin study showed a complete obstruction in four of them. All of them were operated on. In the fifth case it was not clear if the gastrografin had passed through the ileum-cecal valve or not. The unclear clinical picture induced to perform a TC that revealed that a small quantity of gastrografin had passed the ileo-cecal valve but there was a complete small bowel occlusion due to an internal hernia requiring a surgical treatment (thus implying a false negative picture). DISCUSSION: This preliminary study showed that both methods are effective in the early diagnosis of complete SBO. The use of radiopaque markers could avoid some false negatives of the gastrografin method and is significantly less expensive