Borborygmi
You know that noise your stomach makes when you’re digesting? You know- the one that you desprately try to keep quiet when you’re watching a movie with your girlfriend’s family for the first time. Derived from the Greek word, borborygmus, this noise is produced when your bowels are digesting your food.
Trapped air and gas also contributes to the noise! But like yelling at a construction worker for holding up traffic, you really can’t be upset about someone doing their job.