Your body's food factory.

One of the hardest-working, organs in your body is your stomach. Its job is to take food and break it down so your body can use the food for growth and energy. Here's how it works.

Your stomach is made of several layers of strong muscles. These layers crisscross around your stomach, allowing it to expand in almost any direction. This squeezing action helps break food into smaller pieces.

The lining inside your stomach produces hydrochloric acid and other digestive chemicals called gastric enzymes or gastric juices. The acid and juices, combined with the squeezing action of your stomach muscles, soften food into a creamy, soup-like substance.

After your stomach has worked on the food for an hour or two, a muscle at the bottom of the stomach, called the pyloric sphincter, opens for a few seconds at a time. It lets a small amount of the liquid stomach contents, called chyme (kime), move into your small intestine. More digestion occurs there.

Normally, your stomach is emptied in three to six hours. The higher the fat content of your food, though, the longer the process takes. A candy bar would take longer to digest than a carrot.

As your stomach empties, it returns to its normal size. The squeezing action continues, however, even if there's no food in your stomach. These contractions cause loud, rumbling noises when your stomach is empty and hollow. It's your stomach's way of saying, "Feed me!"