Ask A Scientist© Biology Archive

Author:      Dennis R. Colgan
Text:        Why do Stomachs Growl?

Response #:  1 of 2
Author:      wizkid
Text:        The stomach is a muscular organ, which has many digestive roles.  
It is always churning and moving, contracting and digesting.  When it is full 
of food, it is happily doing its job.  But when it is low or empty, it is 
still contracting.  You feel it and hear it because the walls of the stomach 
are rubbing past each other, rather than the food that should be there.  It is 
a way your body tells you to eat something!  However, after a few more hours 
without food, the churning ceases, as the body starts to use stored fat for 
fuel, not ingested food.  The body begins its "starvation mode" and conserves 
energy, lowers metabolism, and burns stored fat.

Response #:  2 of 2
Author:      psych
Text:        Another reason to hear that noise is because when a stomach is 
not full of food it is more apt to get more air into it.  So as it does it is 
work (what it does it a lot like what you do to a push up ice pop) if there is 
air in the stomach it get pushed in bubbles back and forth and you hear the 
bubbles gurgling back and forth.