What is the main function of the lower intestine?

The main function of the lower intestine, specifically the colon (or large intestine), is to remove waste food products from the body. It plays a crucial role in the final stages of digestion, where water is absorbed from the indigestible remnants of food, and the remaining material is formed into stool. The lower intestine is also involved in the storage of fecal matter until it is expelled during the process of defecation. While the absorption of some vitamins and minerals takes place in the lower intestine, its primary purpose centers on the elimination of waste, making it essential for maintaining the body’s homeostasis by preventing the buildup of unhealthy substances.

In the context of the other options, the lower intestine is not primarily responsible for nutrient absorption, protein digestion, or hormone production; these processes occur mainly in other parts of the digestive system, such as the small intestine and specific endocrine glands. Thus, the function of waste removal is the most accurate representation of the main role of the lower intestine.