What is the definition or description of: intestine?

Most of the gut.: The gastrointestinal tract starts at the mouth, travel down the tunnel (esophagus), which connects to the stomach, which then empties into the duodenum, jejunum, and ileum---the three parts of the small intestine (@25 feet). This empties into the colon or large intestine (about 5 feet), which then becomes the sigmoid colon, rectum and out the anus. So, every morsel eaten goes on long journey.