The problem may have something to do with your diet.
If you take a fair amount of coffee, tea and alcohol, (as well as a large amount of fluids), you may need to get up at night to void.
Another thing to consider is diabetes, one of the symptoms would involve pissing a lot, so it may good to have yourself screened.
Well the one thing i don't drink is coffee, tea and alcohol, most times its only iced tea,water,juice or about 1 or 2 cans of soda a day....it just seems like perfect timing, every about 25 days this starts,,...its just that its just so urgent that i have to go! it comes on so fast that i have about 30 seconds to get to a bathroom! and sometimes i just have no control over it if i wait a little bit longer...
thanks for the info
The iced tea may be contributory.
Another thing to consider is that the problem may not be with obstruction but with the bladder. There are some age related changes in the capacity of the bladder to determine when it is full to capacity and hence there is a tendency to empty even when the bladder is not yet really full.
There are a studies that determine the dynamics of the bladder. Perhaps this could be another avenue to consider.