ATI Pathophysiology Practice Exam

Which of the following structures is primarily responsible for the absorption of water in the digestive system?

1. Stomach

2. Small intestine

3. Large intestine

4. Pancreas

The correct answer is: Large intestine

The large intestine, also known as the colon, plays a crucial role in the absorption of water from the indigestible residues of food. As the materials from the small intestine enter the large intestine, much of the water in the remaining waste products is absorbed, which helps to solidify the stool and maintain the body’s fluid balance. This occurs primarily in the ascending colon and continues in the transverse and descending colon. In contrast, while the stomach is responsible for the initial breakdown of food and has some absorption abilities, particularly for alcohol and certain medications, it is not the primary site for water absorption. The small intestine is primarily involved in the digestion and absorption of nutrients and some water, but it is not as effective in water absorption as the large intestine. The pancreas, meanwhile, is essential for producing digestive enzymes and bicarbonate to aid in digestion but does not directly participate in water absorption. Therefore, the large intestine is recognized as the primary structure for water absorption in the digestive process.