Value of water-soluble contrast (meglumine amidotrizoate) in the diagnosis and management of small bowel obstruction.

Introduction: The object of the present study was to determine the effectiveness of a water-soluble contrast follow-through study for differentiating complete from incomplete small bowel obstruction (SBO) and for predicting the need for surgery.

Methods: This prospective study was conducted at Riyadh Medical Complex, Saudi Arabia and spanned 2 years. All adult patients admitted with SBO were included, except those with obstructed hernias, peritonitis, or postabdominal irradiation. The initial resuscitation meglumine amidotrizoate (Gastrografin) follow-though was performed and was considered positive for complete obstruction if the contrast failed to reach the colon as shown on the 24-hour film. Patients were operated on only if they developed signs of strangulation or failed to improve within 48 hours.

Results: Our study group consisted of 73 patients, 48 (65.7%) of whom were male. The mean age was 35.70+/-12.65 years. In 60 (82.2%) patients, contrast reached the ascending colon within 24 hours, giving a definitive diagnosis of incomplete obstruction; among these 60 cases, 49 (81.7%) resolved on conservative management. The other 13 (17.8%) patients were diagnosed as having a complete obstruction; 4 (30.8%) of them were treated conservatively, and 9 (69.2%) underwent surgery. Therefore the sensitivity, specificity, positive predictive value, and negative predictive value for meglumine amidotrizoate follow-through as an indicator for operative treatment of SBO were 45.0, 92.5, 81.7, and 69.2, respectively. The P value using Fisher's exact test was 0.0006.

Conclusions: We can confidently diagnose complete and incomplete SBO and differentiate one from the other. This accurate diagnosis indicates a high chance of success with conservative management for incomplete obstruction but does not always correlate with the need for surgical intervention.