Malignant means that it can spread, or metastasize, to other parts of the body. The small intestine, or small bowel, is part of the digestive system. It is a hollow, tube-like organ in the abdomen. The small intestine is made up of the duodenum, jejunum and ileum. The duodenum receives partially digested food from the stomach. Digestive juices and bile are added to the food in the duodenum, and then the food is passed to the jejunum.