Stomach enzymes are found in digestive juices created by cells in the stomach.
These juices also contain a very strong acid. The enzymes in the stomach work best in the acid. The acid kills the harmful bacteria that map be present in some materials that enter the stomach. The stomach is protected from the acid by a special lining. From the stomach, food passes through to the small intestine. Even though food never actually enters the liver, the liver still plays an important part in digestion. The liver secretes certain digestive fluids that reach food as it enters the small intestine.
Most digestion occurs when food reaches the small intestine. As food passes through the small intestine, it continues to be broken down by enzymes produced in the small intestine itself and by those produced in the liver and passed to the small intestine. The nutrients broken down by digestion are absorbed into the body through the walls of the small intestine. Blood in tiny blood vessels in the intestinal walls, called capillaries, picks up the nutrients from the digested food and takes them to cells throughout the body where they can be used. The food is continuously broken down until the nutrients are in a form that is usable by the cells of the body.
The final organ in the digestive system is the large intestine. While no digestion occurs here, this is a very important step. As the remaining undigested food passes through, the large intestine reabsorbs available water back into the body. The water is taken into the blood through capillaries in the intestinal wall. Then the blood takes the water and redistributes to other cells. What is left is the remaining material from food that the body does not need. The large intestine then passes this remaining waste out of the body.