Had the symptoms for a long time. The other day I did the four way stretch and this relived the pain from my buttock and back. Thing is, in the morning I went to toilet like normal!!
Hope this helps someone.
What's the four way stretch?
Pleased it helped, whatever it is!
http://chirocentre.co.uk/figure-of-four-stretch-piriformis-muscle-stretch/
Sorry I meant figure of four