This topic comes up periodically. I think some of the frequency of course comes from some pretty traumatic action on the bladder, the urethra, the sphincter, and of course, Willie.
I think some of it also comes from continence retraining. In our effort to insure that we don't wet our pants, we begin to empty our bladder every time we feel a pressure. I think our body becomes used to that, so it begins to tell us it's time to go, there's a little pressure down there.
I am admittedly a lazy fellow when it come to being in bed. Prior to surgery, I would not get up in the night. No matter how bad I had to pee, I would lay in the fetal postion , and wait until the alarm clock went off. Generally, my bladder would accomodate the stretching, and I rarely got up in the night.
After surgery, I would get up 2 or 3 times in the night, so I wouldn't wet the bed. Once I get up, I have a hard time going back to sleep. I hate it. So, I began the same routine. Laying there longer until I just couldn't stand it any longer. I found that each night I could make it a little longer.
Now I am back to pre-surgery habits. In bed by 11, don't get up til 7. Also, I try not to drink a lot about an hour before I go to bed. Got to have a glass of milk tho.
Good luck. A lot of these issues seem to work themselves out with time.