system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:What makes your stomach hurt when you are hungry and what causes your stomach to growl?
gpt
The growling is called borborygmi and it's caused by fluids and gasses moving through the intestine, not the stomach. The stomach sits left orientated, partially in the ribcage, wedged just below the diaphragm and part of the liver.

The stomach itself is pretty thick and relatively deep in comparison to the coils of intestine found in the soft, superficial portion of your gut. You shouldn't be hearing much of anything from there when it is empty. Usually borborygmi is more specifically sounds in the large intestine. If you put your ear to someone's stomach area you're more likely to hear the exact stomach noises. 

So why noises when your stomach feels empty? Food sits in your stomach for about 2 hours on average, getting churned around and broken down into a more fluid state called chyme. Then it passes to your small intestine, emptying the stomach. This is where things have the potential to become noisy! Everything moves down the line at this point- chyme from stomach to small intestine, undigested remains from small intestine to large. As well, both stages of intestine spend several hours digesting- peristalsis (more churning) of the food mass in the small intestine where additional digestive enzymes are mixed in and the majority of nutrient absorbtion takes place, then mostly reabsorbtion of water (not churning) in the large intestine as the leftovers are slowly made into poop that go into the rectum for storage and expulsion. 

Once all the food moves down, stomach is ready for a new job and feels left out from all the action the intestine gets to have! Also realize your stomach contracts a lot for its digestive process and you don't feel it so much then, but you might feel it as it expells food to the small intestine. The body isn't particularly good at identifying where the stomach is. Most of your guts don't cause pain directly at their site, the body doesn't quite know where they are, this is why we feel heart attacks down the left arm with some chest tightness and not stabbing heart pains.