Ostomy is surgery to create an opening from inside the body to the outside.
Ostomy is an operation to create an opening (a stoma) from an area inside the body to the outside. Colostomy, ileostomy, and urostomy are types of ostomies. The surgically created opening is called a stoma. Waste and fluids from inside the body are expelled through the stoma and are usually collected in a bag covering the opening.