The excretory system is the system the body uses to filter waste. Food travels through the esophagus, stomach, small and large intestine, pancreas, gallbladder and liver. Your body absorbs important minerals, fats, vitamins and carbs. The musces in your esophagus move the food along in about 2-3 seconds. The stomach's acids break down the food. The liquid mixture files into your small intestine. The small intestine absorbs what you need, while the large intestine then absorbs the last of the minerals. The hard remain rests in your colon, where it then will exit.