What is the main function of the large intestine?

The main function of the large intestine is indeed to absorb water. After food has been processed in the small intestine, where most nutrient absorption occurs, the waste material or chyme enters the large intestine. Here, the large intestine plays a crucial role in reabsorbing water and electrolytes from this material, which helps to consolidate it into a more solid form, leading to the production of feces. This water absorption is vital for maintaining hydration and the body's electrolyte balance.

The large intestine also serves to house beneficial gut bacteria that further assist in the fermentation of undigested materials, but its primary role centers on the absorption of water. In contrast, the small intestine is primarily responsible for nutrient absorption, while enzyme secretion is a function typically associated with organs like the pancreas. Protein digestion occurs predominantly in the stomach and small intestine, with the large intestine playing little to no role in this process.