The small intestine is the primary site for the complete digestion of all major food components: carbohydrates, proteins, and fats. It receives digestive juices from the pancreas and liver (bile), along with its own intestinal enzymes, to break down food molecules into their simplest forms for absorption. The stomach primarily digests proteins and churns food. The large intestine mainly absorbs water and forms faeces, while the oesophagus is a food pipe that transports food to the stomach.