How many of us have had our stomachs growl at embarrassing times? Technically, this loud cry for food is called borborygmi. It's the name of those sounds your stomach makes when its hungry. The word even sounds like stomach rumbling. Try it: borborygmi.
Borborygmi are the sounds that happen when fluids and gas are forced through the intestines. When our brain tells us its time to eat, a reflex kicks in that makes the stomach walls contract. The contractions cause the digested food in the intestine to move down towards the rectum. Even if there's no food there, the small amount of fluid and mucus in the stomach combined with all that movement in the intestines make burbling and gurgling sounds. That's borborygmi.