How useful are bowel sounds in assessing the abdomen?

Abstract

Background: The purpose of our study is to determine the accuracy of bowel sounds in the diagnosis of ileus and bowel obstruction.

Methods: Healthy volunteers (n = 10) and patients with radiologically or laparotomy confirmed small bowel obstruction (n = 9) and ileus (n = 7) were enrolled. Two 30-second recordings from each subject were obtained using an electronic stethoscope. Study physicians (n = 20) were then presented with 43 recordings in blinded fashion and were asked whether each was from a normal subject or from a subject with bowel obstruction or ileus.

Results: Physicians arrived at the correct diagnosis a median of 30 times out of 43 (69.8%). Intra-observer variation (κ = 0.72, agreement 81.3%) and intra-subject variation (κ = 0.63, agreement 78.7%) were very good. Bowel sounds from subjects with ileus and normal bowel sounds were correctly identified most of the time (84.5 and 78.1%, respectively). Bowel sounds from patients with obstruction were correctly identified only 42.1% of the time, but if a physician believed he or she was hearing a bowel obstruction, this had a strong positive predictive value (PPV, 72.7%).

Conclusion: Our results suggest that the auscultation of bowel sounds is useful, especially in detecting ileus. The diagnosis of obstruction had a high PPV.