An interesting finding was recently discovered in nurses who work rotating shifts.  These nurses were found to have a higher prevalence of irritable bowel syndrome (IBS) and abdominal pain than nurses with a more regular schedule.  More interesting was that this link had nothing to do with sleep quality. 

There is a good explanation for this.  The colon has its own internal clock which follows sleep patterns.  This is why we are more likely to have a bowel movement in the morning.  But when sleep patterns are changed – even if adequate sleep is experienced – this can throw off the regularity of the colon, which can result in symptoms of IBS. 

This makes total sense.  Have you ever traveled to a different time zone, only to have your bowel movement completely change schedule?  Well, now you know why.