What is the primary function of the lower GI tract?

The primary function of the lower gastrointestinal (GI) tract is to absorb nutrients and remove waste. The lower GI tract consists of the small intestine and large intestine. In the small intestine, the absorption of nutrients like carbohydrates, proteins, and fats occurs after the food has been digested. The leftover material moves into the large intestine, where water and electrolytes are reabsorbed, and the remaining waste products are formed into stool for elimination from the body. This efficient process ensures that the body retains essential nutrients while disposing of non-essential waste, making it a critical component of digestion and overall health.

Other options, such as producing bile and manufacturing digestive enzymes, are functions more closely related to the liver and pancreas, respectively, while regulating blood sugar primarily involves the actions of hormones like insulin produced by the pancreas. Therefore, the focus of the lower GI tract is specifically on nutrient absorption and waste removal.