This research study is for patients with adhesive small bowel obstruction (ASBO). ASBO is a condition in which the small intestine gets blocked due to scars called adhesions. To see the blockage, a contrast agent is given and an x-ray is taken of the belly (abdomen). MD Gastroview and omnipaque are two contrast agents that may be given as part of your normal care for ASBO. This study hopes to see if one is better than the other.