I’ve had it since August. I’ve had a course of physio and I’m unfortunate for that to have had no effect. I’m having 3 weeks of full time physio / rehab therapy in March in an attempt to nail it. You do need to be sure that it is piriformis and if you are lucky, the stretches etc will sort you better than me.
Working on aductor and abductor muscles is suppsed to be very good for it. A ‘spikey ball’ is better than a tennis ball – google and you’ll find them.
My pain centres in the left buttock and radiates up and down, more down, as far as the back of my knee. It can be cripplingly sore. If you have any loss of sensitivity in the groin, pins and needles or numbness, get a doc to look immediately – all ‘red’ indicators of associated issues.
HTH a bit.