Food/liquid/gas are moving through your stomach to your intestines - stomach growling is a part of digestion. When there is a lot of food in your stomach the sounds are muffled, when your stomach is empty you can hear the “growls” easier.
I learned that the growling does not indicate hunger as we are often told. It indicates your stomach is empty which does not automatically mean you’re hungry. When your stomach has nothing to digest it frees up your body’s energy and focuses it in other areas. This is why people find fasting beneficial.
Thanks,
Eddie