Understanding the Gastrointestinal Tract Understanding Your Body’s Digestive System To better understand the treatment options available, it is best to know how your body digests, processes, and stores food. 1. Food enters the esophagus. 2. Once through the esophagus, food travels to the stomach for processing. Here it is reduced to small particles and liquefied by the stomach’s acids. 3. Slowly, in small amounts, the food travels to the small intestine where it is digested further and absorbed into the body. 4. Vitamins and minerals are absorbed. 5. Waste products and unused remains are passed and eliminated into the colon. Digestion and Absorption Calories are absorbed and used for the body’s energy. If the number of calories absorbed exceeds the number of calories used, then the body converts the remaining calories to be stored as fat. Often individuals who are obese have lower calorie needs compared to those who are at an ideal body weight and are prone to weight gain as excess calories go unused.