Surgery to remove part of or the entire colon is called colostomy. During colectomy, a surgeon will remove the part of the colon containing the cancer as well as the maringal area close to the cancer. In addition, nearby lymph nodes are also usually removed. Depending on the extent of the colectomy, the healthy portion of the colon will either be reattached to the rectum or attached to an opening in the wall of the abdomen called a stoma. This latter option is called a colostomy, and waste will exit the body through the stoma into a colostomy bag instead of exiting through the rectum.