Role of ultrasound in determining small bowel intestinal obstruction: Findings at a public sector hospital of Pakistan

Background: Intestinal obstruction accounts for nearly 20% of surgical admissions for acute abdominal conditions. Keeping in view the wide array of etiological causes, prompt diagnosis of intestinal obstruction as the etiological cause behind acute abdominal pain is often difficult and deferred. In the present study, we evaluated the role of ultrasound in diagnosing intestinal obstruction of the small bowel in the setting of a public sector hospital of Karachi. Methods: This was a retrospective analysis of 150 patients who presented with small bowel obstruction at Civil Hospital, Karachi (June 2011 to June 2012). Those that underwent a pre-laparotomy abdominal ultrasound were included while mixed bowel obstruction or incomplete files were excluded. Ultrasound was used to identify the presence of obstruction, cause of obstruction, site of obstruction and presence of mass. All radiological findings were matched with surgical notes of laparotomy. Results: Abdominal ultrasound failed to detect mechanical obstruction in only 18.7% (n=28) cases (sensitivity 81.33%). However, ultrasound was not very effective in distinguishing the segment of bowel involved in obstruction in almost half the cases (56%). Ileo-jejunal loops were the most common site of obstruction as identified by ultrasound and later discovered upon laparotomy. The most common etiology reported was tuberculosis (30.7%), adhesions (24.7%), hernia (17.3%) and mass. Ultrasound detected mass as etiological cause in 14 out of 30 cases. Conclusion: Ultrasound is a cheap, safe and efficient mode of diagnosing mechanical intestinal obstruction involving small bowel in public sector hospitals.