Shift Work May Precipitate Irritable Bowel Syndrome Symptoms

Irritable bowel syndrome (IBS) is the most common functional bowel disorder, and is characterized by abdominal pain, constipation, and diarrhea. These three symptoms are also reported by shift workers.  To investigate a possible link, Ann Arbor researchers studied survey data from nurses, some of whom worked rotating shifts between day and night.  Their findings are reported in the American Journal of Gastroenterology.    

Nurses working in patient care were asked to complete two questionnaires – one was the Rome III IBS quality-of-life measure, and the other a modified sleep-50 questionnaire.  Those 399 nurses who returned questionnaires were grouped into 3 classes – those working day shifts (214), night shifts (110), and rotating day-night shifts (75).

The rotating-shift nurses had a significantly higher percentage with a score diagnostic of IBS – 48% compared to the day-shift nurses’ 31%.  Significantly more of them also had abdominal pain – 81% vs. 54% for day-shift and 61% for night-shift nurses. These differences were independent from the sleep quality scores. 

Normally the biological clock in the body (the circadian rhythm) encourages a bowel movement in the first 6 hours of the day.  Many ‘regular’ people have a bowel movement shortly after breakfast.  Shift work can produce disruption of the circadian rhythm, and rotating shift work demands constant readjustment of the rhythm.  This is probably the reason for the increased abdominal pain and symptoms of IBS seen in the rotating-shift nurses in this study.

People with gastrointestinal symptoms can get good advice from the Michigan Bowel Control Program.  It explains the common and less-common GI disorders, with text, videos and information on procedures.