The digestive tract is a continuous tube that breaks food down into nutrients that can be absorbed. Once food enters the stomach, it begins mixing with digestive juices and is passed into the small intestine a little at a time. As the food passes along the small intestine, which is actually over twenty feet long, the nutrients are absorbed through the wall of the intestinal tract and passed into the bloodstream.
By the time the food has reached the large intestine, also called the colon, the nutrients have been removed and waste materials remain. In the colon, the waste material is passed along by a series of muscle contractions, called peristalsis, and eventually, the waste reaches the end of the digestive tract, the rectum. The colon absorbs water from the waste material, but if the muscle contractions are not normal, a change in bowel habits can occur. The digestive tract or gastrointestinal tract.