Before i had radiotherapy i asked the onco about the spacer in July 2019 and he told me i would have to go private and i would have to go to the Nuffield Vale hospital in Wales for the operation.
The operation was called Bioprotect Balloon Procedure.and cost me about (cant remember exact cost) £6000
plus a hotel the night before.
After radiotherapy i had no problems with back passage but had & still have an over active bladder but that maybe because i had problems with RT.
Hope this helps