What is the function of the large intestine?

The large intestine primarily functions to store waste for elimination. After food is digested and nutrients are absorbed in the small intestine, the remaining indigestible food matter, along with water and salts, is passed into the large intestine. Here, water is reabsorbed, turning the remaining material into a more solid form, which is ultimately stored in the rectum until it is eliminated from the body during a bowel movement.

In this process, the large intestine also plays a role in the fermentation of undigested materials by the gut microbiota, contributing to the overall health of the digestive system. Its primary emphasis, however, is to prepare waste for excretion rather than nutrient absorption or digestion. Other functions such as secreting bile and digesting proteins are associated with other organs, such as the liver and stomach, which further clarifies why the function of storing waste is the correct answer in this context.