Medical Assistant Certification (MAC) AMCA Practice Exam

What is the primary function of the large intestine, also known as the colon?

1. Absorb nutrients

2. Absorb water

3. Produce bile

4. Store waste

The correct answer is: Absorb water

The primary function of the large intestine, or colon, is to absorb water from indigestible food matter. As food passes through the digestive system, it becomes less liquid in the large intestine as water is absorbed back into the body, helping to form solid waste (feces). This process is essential for maintaining fluid balance and preventing dehydration. While the large intestine does play a role in storing waste before it is excreted, the key distinction of its primary function is its role in water absorption. The colon also helps to compact waste and house beneficial bacteria that further assist in the digestive process, but these functions support the main role of water absorption. Other choices, such as nutrient absorption and bile production, primarily occur in the small intestine and liver, respectively, further solidifying the large intestine's main task of water reabsorption.