Digestion of food begins in the mouth. Special proteins known as enzymes begin to digest the food so it can be used by the body. When you swallow, the partially digested food passes through a tube called the esophagus and into the stomach.
The stomach is a muscular pouch that churns and mixes the food into a semi-liquid form. Next, the food passes into the small bowel, also called the small intestine. Most of us have 6.5 to 7.5 m (22 to 25 ft.) of small intestine, which is divided into three sections:
• the duodenum is 31 to 38 cm (1 to 1½ ft.) long
• the jejunum is 2.5 to 3 m (8 to 10 ft.) long
• the ileum is 3.5 to 5 m (12 to 16 ft.) long.
The ileum, the last section of the small intestine, connects with the large intestine, or colon. The absorption of food nutrients occurs mainly in the jejunum and ileum. By the time food arrives in the colon, the process of digestion and absorption is almost completed. Thus, most material passing into the colon is waste.
