Yes they find out. It's called a pain contract and they state clearly only they can prescribe pain meds for you while you are seeing them. Read the contract. Also EVERY STATE now has a prescription monitoring program that every prescriber and pharmacy can see on the website who you get meds from. You really need to get informed before you get in big trouble. Every legit PM doc will find this scenario sketchy. You think you are being clever, but they have heard it all 1,000 times before you blurt it out. Wise up.
Since you're in pain management you can not get pain meds from any other Dr. Read your contract, I'm sure it's all in there. If you do get pain meds from another Dr and your PM Dr finds out you will most likely be released and could be black balled if you try to get in to another pain clinic.
I know it's not fair. The contracts aren't fair, the urine tests aren't, and having to drive so far every month isn't fair.
Have you checked to see if there is another pain clinic closer to you? That would be the best thing to do.
Another thing, almost no family Dr will prescribe any kind of pain meds any more. That's why we're all getting thrown in to pain clinics.