Effect of Stretching on the Electroencephalography of People With Irritable Bowel Syndrome.

Introduction Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic abdominal pain and altered bowel habits without structural abnormalities. Irritable bowel syndrome affects approximately 9.3% of the Japanese population based on Rome III criteria, with higher prevalence observed in younger adults, and is associated with significant impairments in quality of life. Its multifactorial pathophysiology involves dysregulation of the brain-gut-microbiome axis, with altered brain activity, such as reduced alpha and increased beta power on electroencephalography (EEG) during eyes-closed resting states. Although nonpharmacological interventions such as abdominal and trunk stretching have demonstrated potential in reducing psychological stress markers, their neurophysiological effects in individuals with IBS remain poorly characterized. This study aimed to investigate the neurophysiological and somatosensory effects of a brief abdominal stretching intervention in patients with IBS. We hypothesized that stretching would (1) increase frontal alpha power and (2) increase somatic sensory and pain thresholds. Methods Fourteen adult males (mean age, 23.5 ± 1.2 years) with symptomatic IBS based on the Japanese version of the IBS Severity Index completed an Irritable Bowel Syndrome Quality of Life measure, followed by baseline assessments of sensory and pain thresholds and a 10-minute resting-state EEG. Participants performed a 4-minute supine trunk rotation stretching protocol involving bilateral 1-minute holds repeated twice per side until mild discomfort was perceived. Alpha power (8-12.8 Hz) from EEG recordings and sensory and pain thresholds were statistically analyzed using paired-sample Student's