Although humans can survive for about a month without food, but only a maximum of five to seven days without drinking. Nevertheless, an empty stomach announces very loud and audible very quickly. When it comes to food, the stomach talks. And: He "talks" especially when there is nothing to eat.
What is happening?
The food comes through the esophagus into the stomach. There it is mixed with gastric juices and liquefied to a chyme. Over and over again, it is kneaded by the powerful stomach muscles to extract the nutrients and mix with the gastric juices.
If the stomach is now as good as empty, it contracts and through the stomach outlet air is pressed into the intestine. This is not without noises in front of him - the stomach growls. The stomach growl is a mostly clearly audible roaring sound from the abdominal region.
Although one speaks of stomach growls, these sounds can not only be in the stomach, but also in the small intestine or lower intestinal sections arise.
Enteral nervous system
The gastrointestinal tract possesses an independent nervous system, the so-called enteral nervous system. This controls the typical movements - namely the contractions in the muscles of the gastrointestinal tract. Therefore, a full stomach with loud rumble can report. Because it is - actually speaking - intestinal noises, which result from the intestinal movement and the processing of the chyme.
That means: stomach growls and gut rumbling are completely natural and normal events.