Introduction: An acute abdomen is defined as a clinical condition characterized by severe abdominal pain developing suddenly over several hours or less. Ultrasonography (USG) helps the managing surgeons arrive at early diagnosis and rule out alternative diseases, thus reducing negative laparotomy rate. This study analyzed the diagnostic yield of USG in patients with non-traumatic acute abdomen presenting to Surgery department via Emergency department/outpatient department of a tertiary hospital. Methods: This cross-sectional observational study included 110 patients with non-traumatic acute abdominal pain who were sent for USG examination. The percentage concordance of USG diagnosis with the final diagnosis at discharge was determined in terms of sensitivity, specificity, positive and negative predictive values for acute abdomen. Results: Of 110 patients, correct clinical diagnosis was made in 83 patients (75%) while USG made a correct diagnosis in 101 patients (91%). Hence, with the help of USG, accuracy of diagnosing cause of acute abdomen increased by 16 %. The sensitivity and specificity of USG in diagnosis of acute appendicitis were 87.7% and 98.3% respectively. Conclusion: USG is easily available and non-invasive modality without radiation exposure and requiring minimal patient preparation. USG should, therefore, be an important routine diagnostic investigation in patients presenting with acute abdomen.

Keywords: Acute abdomen, Sensitivity, Specificity, Ultrasonography