The symptoms of irritable bowel syndrome (IBS), which include chronic abdominal pain associated with bowel motions of one of four types--diarrheal, constipating, mixed, or unclassifiable are difficult to treat.

When compelled to limit their activities, such as work or travel, due to the sudden and unpredictable need to use the restroom, patients with IBS report a lower quality of life and social discomfort.

While autonomic nervous system anomalies associated with IBS have been studied using 24-hour ECG measurements, no research has, up until this point, looked at changes in the autonomic nervous system during bowel movements. The findings of the study were published online in PLOS ONE.

Associate professor Fumio Tanaka and his research group at the Osaka Metropolitan University Graduate School of Medicine recorded the autonomic nervous system activity of IBS patients and healthy subjects using a wearable device and tracked activities such as defecation and sleep.

As a result, they found that, unlike healthy subjects, the sympathetic nervous system of IBS patients was activated 2 minutes before defecation and persisted until 9 minutes after defecation.

Furthermore, the activation of the sympathetic nervous system was found to be associated with greater abdominal pain and lower quality of life.

"This research is characterised by the fact that autonomic nervous system functions are measured using a clothing-type wearable device, and that lifestyle events such as defecation and abdominal symptoms are input simultaneously in real-time, using a smartphone application originally developed by our group. As a result, autonomic nervous system activity during defecation was accurately evaluated. We hope that further research will improve the quality of life of IBS patients and help elucidate the pathophysiology," professor Tanaka concluded.