Well the double epidural shots didn't relieve all the pain from my sciatic nerve and the DR. said I'm now having problems with the piriformis muscle. 
Now I have to go in for a shot in the but!
Max: You need to stretch the Piriformis muscle in order to stop it from impinging the nerve.
Lay on your back on the ground or in bed.
Bend knees and bring your heels closer to you body (feet on ground)
Let's say the issue is on the right side...
Bend the right knee and put the right ankle above the left knee.
Put one arm between your legs and grab the left knee with both hands (like doing a jack-knife off a diving board)
Pull the left knee towards your chest.
As you pull up you will stretch the right Piriformis muscle.
Repeat this many times over the next days and weeks.
You can also do this in a tub of hot water --- soak for at least 15-20 minutes.
No need to grab with both hands around knee as it puts your spine directly pushing into the bath tub floor...
Instead, put the right ankle above the left knee and with one hand on the top of your foot and the other at the knee, pull evenly so that it pulls the whole lower leg towards you. Then for bonus points pull the knee closer while angling the foot away from you. It stretches the Piriformis a little differently and stretches other muscles too.
Even more effective is to have a Massage Therapist grind their elbow into your glutes to help break down any junk in the muscles, especially if you do the hot soak and stretches right before the appointment!
I hope that you will try this!
