Your digestive tract (or the gut) starts in your mouth and ends at your anus. The GI tract includes your mouth, esophagus, stomach, small intestine, large intestine, and anus. Three other organs are also needed for digestion: the liver, gallbladder, and pancreas. It is through digestion that your body gets the nutrients necessary for energy, growth, and cell repair. Your body must breakdown the foods you consume to useable carbohydrates, protein, fats, and vitamins.