The stomach is a sac shaped like a "j" and is about eight inches long. In the stomach, food is mixed with acids. The muscles in the stomach move, which helps break down the food. The stomach is protected from the acid by a lining. From the stomach, the food pulp is sent to the small intestine. Food leaves the stomach a little bit at a time.

The small intestine is the final place for digestion. Measuring about twenty feet in length, the small intestine is one inch in diameter. Digestive juices released in the small intestine finish breaking down the food.

The food is moved along the small intestine in a squeezing motion known as peristalsis. This motion is much the same as squeezing a tube of toothpaste. All of this movement causes the noise when we say our stomach is "growling."

Lining the small intestine are millions of fingers called villi. These absorb the chemicals that we need from the food into the body. It is at this point the food is actually in the body.

Waste products and food that are not absorbed in the small intestine pass into the large intestine. This waste material is called feces. The large intestine is only five feet long but is larger in diameter than the small intestine. The large intestine includes the colon.

In the large intestine, feces are formed from water, undigested food and bacteria. Water is absorbed back into the body so the waste material becomes more solid as it travels through the colon. It may take as long as twenty hours for food to pass completely through the large intestine.