Sometimes treating diseases of the digestive or urinary systems involves removing all or part of your small intestine, colon, rectum or bladder. In these cases, there must be a new way for wastes to leave the body. The surgery to create the new opening in the abdomen is called ostomy. The opening is called a stoma. There are many different types of ostomy. Some examples are Ileostomy: The surgeon removes the colon and rectum and attaches the bottom of the small intestine (ileum) to the stoma. Colostomy: The surgeon removes the rectum and attaches the colon to the stoma. Urostomy: The surgeon attaches the ureters - the tubes that carry urine to the bladder - to either the small intestine or to the abdominal wall.