In the usual procedure the pouch is attached (stapled) to a short remnant of rectum called a cuff. It should be 1-2 cm long or so. That forms the connection "directly" to the anal canal, with no functional rectum left.

There are other procedures with less rectum left behind, but they are generally only done when necessary, because they have a higher complication rate.

Nora, it sounds like you are having a 3 stage procedure. In that case, the first stage is removal of the colon And an end ileostomy. The rectum is left to make the j-pouch procedure easier. In the second stage the j-pouch is created and attached to a small remnant of the rectum, which is called the cuff. A diverting ileostomy is done at that time. The third stage is the take down of the ileostomy.

Jan