Where does most digestion occur in the small intestine?

The duodenum is the section of the small intestine where most digestion occurs. This is because the duodenum is the first part of the small intestine, receiving partially digested food from the stomach, along with bile from the liver and pancreatic juices from the pancreas. These secretions contain enzymes and bile acids that are crucial for breaking down proteins, fats, and carbohydrates.

While the jejunum and ileum are also important parts of the small intestine, they primarily serve roles in absorption rather than digestion. The jejunum is more involved in nutrient absorption, while the ileum absorbs bile acids and vitamin B12. The cecum, on the other hand, is part of the large intestine and does not significantly contribute to digestion in the small intestine. Hence, the duodenum is specifically adapted for the digestive processes that occur right after the stomach, making it the primary site for digestion in the small intestine.