What percentage of digestion and absorption occurs in the small intestine?

The small intestine plays a critical role in digestion and absorption, handling the majority of the nutrient processing that occurs in the gastrointestinal tract. Approximately 90% of digestion and absorption takes place in the small intestine. This is due to its specialized structure, which includes villi and microvilli that greatly increase the surface area available for nutrient absorption.

The small intestine is divided into three parts: the duodenum, jejunum, and ileum. In these sections, enzymes from the pancreas and bile from the liver further break down food, allowing for the effective absorption of carbohydrates, proteins, fats, vitamins, and minerals. The high percentage of absorption centralizes in the small intestine is essential for ensuring the body receives the nutrients it needs for energy, growth, and cellular maintenance.

In contrast, other parts of the digestive system, such as the stomach and large intestine, contribute much less to overall absorption, emphasizing the small intestine's predominant role in this vital process.