Why does your stomach growl when you're hungry? The rumbling sound called borborygmi happens when your digestive muscles contract to move food and gas along. These contractions occur even when your stomach is empty, producing louder noises because there's nothing to muffle them. The brain actually triggers this activity as a way of preparing for the next meal. So that embarrassing growl during a quiet meeting isn't your stomach complaining. It's your body gearing up and cleaning house for the fo