Adhesive small bowel obstruction (ASBO) is a condition that is commonly found in patients with history of abdominal surgery. The management for such condition can be controversial. In terms of conservative treatment, recent studies have shown conflicting outcomes on whether water soluble contrast would provide benefit in reducing number of patients needed for surgery. In addition, there are a limited number of literature that investigates the role of low-osmolar contrast in reducing operative need in patients diagnosed with ASBO.

The objective of this study is to compare the operative rate of patient diagnosed with ASBO between patients who were treated with low osmolar water soluble contrast (Iohexol) and patients who were treated traditionally.

This study is a randomized, controlled and double-blinded study, where participants who were diagnosed with ASBO will be randomly allocated into two groups:

(i) A contrast group (CG): Patients will be treated conservatively and received Omnipaque (Iohexol) via nasogastric tube

(ii) A traditional group (TG): Patients will be treated conservatively and received sterile water via nasogastric tube

After obtaining informed consent, the patient will be administered with either 100 mL of 350 mg Omnipaque or 100 mL of sterile water via nasogastric tube. The nasogastric tube will be clamped for 1 hour and patient will be positioned with 30 degree head elevation. In the contrast group (CG), surgery is indicated when contrast failed to reach the colon. Failure of conservative treatment is considered when there are no clinical improvements after 48 hours and the patient will then be proceeded for surgery.

Inclusion Criteria:

• Patients who are presented with clinical manifestation of small bowel obstruction due to adhesion and require radiological investigations
• Patients who has history of abdominal surgery over 30 days

Exclusion Criteria:

• Patients with clinical signs and symptoms of bowel strangulation, ischemia, perforation or peritonitis
• Patients with clinical signs and symptoms of bowel obstruction from non-adhesive causes, including malignancy, herniation, inflammatory bowel disease, Crohn's disease, and others.
• Patients who has history of allergy to water soluble contrast agent