Development and Initial Clinical Evaluation of a Stress-Induced Computerized Bowel Sound Analysis System for Irritable Bowel Syndrome

Abstract

Irritable bowel syndrome (IBS) is diagnosed using symptom-based criteria because no established physiological test objectively supports the diagnosis. We developed and evaluated a computerized bowel sound analysis system incorporating a dichotic listening task as a psychological stress challenge in three phases. In Phase 1, a short-time energy (STE)-based bowel sound extraction algorithm showed high sensitivity and specificity in technical evaluation. In Phase 2, six individuals with IBS and 10 healthy controls underwent two dichotic listening conditions in a randomized crossover study. Bowel sounds and heart-rate variability were recorded during consecutive 10-min resting, stress-loading, and recovery periods. Despite no significant between-condition differences, the condition showing numerical LF and HF increases during stress loading in participants with IBS was selected exploratorily. Using this condition, Phase 3 evaluated 15 individuals with IBS and 38 healthy controls. The percentage change in STE from rest to stress loading (rest-to-stress ΔSTE) showed an AUC of 0.79 (95% confidence interval, 0.66–0.91), with 0.80 sensitivity and 0.68 specificity at an exploratory cutoff of 20.1%. Computerized bowel sound analysis during psychological stress showed preliminary potential as a non-invasive physiological adjunct for distinguishing IBS from healthy controls. Validation in larger independent cohorts is required. J. Med. Invest. 73 : 503-518, August, 2026