Early intestinal obstruction is easily misdiagnosed. Many physicians consider terminal bouton if computed tomography (CT) scan is done. However, different examinations provide diverse information and significance. This retrospective, randomized, clinical study investigated the diagnostic value of three imaging modalities for intestinal obstruction, supine and upright (or decubitus) plain abdominal radiography, contrast radiography using Gastrografin, and 64 multi-slice spiral CT (MSCT). A total 142 patients with intestinal obstruction were examined. The diagnostic accuracy of plain radiography, contrast radiography, and MSCT for detecting small bowel obstruction was 62.5, 85, and 77.5 %, for localizing the obstruction was 0, 90, and 78.75 %, and for determining the cause of obstruction was 0, 71, and 65 %, respectively. The diagnostic accuracy for detecting large bowel obstruction was 53.23, 73.17, and 92 %, and for localizing the obstruction was 38.17, 60.98, and 98 %, respectively. The diagnostic accuracy of MSCT in determining the cause of obstruction was 91 %. None of the patients administered Gastrografin experienced any adverse effects. In conclusion, MSCT has great diagnostic value in identifying the site and cause of intestinal obstruction, especially in cases of large bowel obstruction. Contrast radiography using Gastrografin was effective in diagnosing and treating small bowel obstruction, making it a beneficial adjunct to MSCT.