Piriformis Syndrome: How were you diagnosed and what helps?

I believe the symptoms of Piriformis syndrome and back problems are quite different. My symptoms right now are clearly Piriformis symptom. I have no back pain. My pain is in my butt, down the thigh and leg to my ankle. I can't sit or walk without pretty bad pain. I just had a steroid injection 2-days ago into the Piriformis muscle ---- I got no relief at all. This is the 2nd steroid injection I've had in less than one month. I'm not going to have any more. They don't work for me and I'm not going to waste my time getting any more injections. I need a new MRI (Pelvic MRI) to firmly diagnose Piriformis syndrome and my physician needs to come up with a treatment plan that works or refer me to another physician who can help me with this pain which I believe is a combination of Sciatica and Piriformis syndrome.

I am very interested in this subject, though I've never heard of piriformis before. Lately I've been having pain (aching and sharp pain both) that radiates from my back around where my kidneys are, down my buttocks to my legs. Sitting or laying in bed makes it worse; if I get up and move around it sometimes helps. I haven't been to the doctor yet. It just seemed to come on all of a sudden. No falls, no strains, no injuries. Help! Where should I start?

I've had piriformis syndrome, diagnosed by my PCP, and Physical Therapy fixed it.

So you didn't go to an orthopedist? Why? And how can they tell the difference between piriformis and sciatica?

I did not go to an orthopedist. My very experienced & knowledgeable PCP at the time diagnosed it and recommended PT. In just 6 sessions it was resolved.