Your digestive or gastrointestinal system breaks down and absorbs food to give your body the energy it needs. The digestive tract starts at the mouth and continues through the esophagus to the stomach and then the small and large intestines. Your digestive system also excretes waste products from your food, drink, and medication intake. The excretion process involves the large intestine, also called the colon, which is six feet long. There are many issues related to digestive health.