Surgical opening in the body, or the operation creating it, usually to allow discharge of wastes through the abdominal wall.
It may be temporary, to relieve strain on damaged organs, or permanent, to replace normal channels congenitally missing or surgically removed (usually to treat cancer). A loop of bowel (the colon in colostomy and the ileum in ileostomy) is cut and the end brought through to the abdominal surface. Waste usually exits into a self-adhering bag worn over the opening, or an internal pouch may be made from body tissue.