(I hope you are using a doctor with lots of experience.)
I have been using the Medtronic Interstim device since 2016 with good results. It treats my urinary urgency and frequency problem. During the night I was having to go every 30 minutes, but now I am able to wait for upto 3 hours. That makes a big difference for me.
I had to do a trial using an external version for a week or so. I determined that it had enough benefit to go ahead with the permanent install. The permanent version worked much better. However, getting the correct program and amplitude combination is something that took some time to get right.
There are about 100 different programs that can be loaded on to the remote controller, but it only has 4 channels to hold them. You can switch to any of those channels at any time, but you have to go back to your doctor to load different programs onto the remote.
I had to replace the first device sooner than expected because I had drained the battery by having the amplitude set too high. The doctor repositioned the electrical wires that carry the signal to make it more effective.
Be aware that your device may or may not be MRI friendly. Mine is not, but my doctor tells me that my next one will be MRI friendly and have longer lasting batteries. That is good news.
Some suggestions:
* Think about where on your body you want the internal device to be implanted. In my case, I asked that the device be on my back above my beltline. (I don't have much fat on my butt, so I didn't want to be sitting on it or sleeping on it.)
* When you decide to change to a different channel, first turn down the amplitude for the current channel. For some reason, if you ever go back to that first channel, it will be painfully shocking. Then slowly turn it back up.
* Sometimes it can surprise you with a shock when you shift your body position. In my case, it happens when I am sitting up in bed to read. No problems any other time.
* Carry the remote with you at all times.
* Keep a ready supply of batteries with you for the remote controler. The remote really eats them up, even if you hardly use it.
For me it has been a real blessing, but everyone is different. I hope it helps you too.
May the Lord bless you and help you.