Which describes a primary function of the large intestines?

• A. Secretion of digestive enzymes
• B. Absorption of proteins in the stomach
• C. Filtration of blood
• D. Fecal material formation, fluid absorption

Answer: (D)

The large intestine mainly reclaims water and electrolytes from indigestible material and forms solid waste. After most nutrients have been absorbed in the small intestine, the remaining material passes into the large intestine where water is absorbed to concentrate waste and stool is formed for elimination. It does host bacteria that ferment some fibers and can synthesize certain vitamins, but it does not secrete digestive enzymes to break down nutrients, nor is it the primary site for protein absorption or blood filtration. These roles belong to the stomach/small intestine and the kidneys, respectively. So, fecal material formation with fluid absorption best captures the large intestine’s primary function.