According to MedlinePlus, the stomach is connected to the first part of the small intestine, which is called the duodenum. Food mixes with stomach acid and moves to the duodenum, where bile is mixed in from the gallbladder and digestive juices come from the pancreas.
MedlinePlus states that the duodenum is also where minerals, vitamins and other nutrients begin to be absorbed from food.
WebMD explains that the small intestine is divided into the duodenum, the jejunum and the ileum. The small intestine measures approximately 20 feet in length and 1 inch in diameter. The large intestine measures approximately 5 feet in length and 3 inches in diameter.