An ileostomy is used to move waste out of the body when the colon or rectum is not working properly.The word "ileostomy" comes from the words "ileum" and "stoma." Your ileum is the lowest part of your small intestine. "Stoma" means "opening." To make an ileostomy the surgeon makes an opening in your belly wall, brings the end of the ileum through the opening. The ileum is then attached to the skin.