Miley,
Like Izzy said.
With exception of the night before surgery; your stay in the hospital will be in a hospital gown. All I took to the hospital was my purse, a pair of PJs, house shoes, and my iPad, and phone. Upon return to the recovery house I only used (2) pair of pajamas (they were kind enough to wash my pjs twice because of unforeseen circumstances). They provide underwear, pads, and pretty much everything else. I would make sure to bring (2) bars of dove soap as you will use that for each shower and sitz bath. Izzy brought me a 2nd bar just in case.
What I would suggest:
Two or three pair of pj's, house shoes, robe, entertainment, soap, and as Izzy said something to wear outside. Mainly, what the staff suggest is a very good guide.
Also for the trip home comfy, loose fitting clothes. I decided to NOT wear either dress that I brought for the trip home as my ability to sit in a ladylike way (legs closed or crossed) was somewhat compromised by the swelling. Jeans were also not possible, I choose a pair of loose fitting, soft cotton slacks that worked well.
I did not require extra room in the suitcase for the sitz bath as they were now having you take that in the bath tub.
Also a suggestion if you are flying. Make sure to pack absolute necessary items in your carry on, my checked bags did not make it to Montreal till a few days later. They were at the recovery house by the time I returned, but ........
Kristin