hiya,
i stayed overnight on friday, i just took a pair of slippers and dressing gown for walking to theatre in, a few little snacks for after surgery incase you miss meal times, maybe a book or magazine incase you are kept waiting a short while (although there is tv with freeview channels in your room) and some baby wipes just to freshen up the next day before i was discharged. i also took my v-pillow with me but i ended up not needing it as they prop the bed up for you and give you plenty of pillows
its up to you if you want to take pajamas or something although i ended up sleeping in my gown as i was operated on quite late and didnt feel up to changing, its also easier if you have drains attached as they wont get caught anywhere.
thats all i can think i needed! if i think of anything else il let you know
good luck! xxxx