The entire procedure can be performed in one operation, but is usually split into two or three. When done as a two-step, the first operation (step one) involves a proctocolectomy (removal of the large intestine and rectum), and fashioning of the pouch. The patient is given a temporary defunctioning ileostomy (also known as a "loop ileostomy"). After a period of usually 6–12 weeks the second step (sometimes called the "takedown") is performed, in which the ileostomy is reversed. The reason for the temporary ileostomy is to allow the newly constructed pouch to fully heal without waste passing through it, thus avoiding infection.