Growling stomach, hidden dragon?

What exactly causes one’s stomach to “growl”? Is it actual hunger? Weird combo of gastric juices? Muscle spasms?

Any insight would be greatly appreciated.

the answer is here.

Thanks!

The Straight Dope Staff also took a shot at Why does your stomach growl?

Just to note that the two links given refer to two different things. Q.E.D.'s link was about true stomach noises. The staff report included a separate cause of noise, gas moving through the intestines, which is what Tech meant by borborygmus.