Trouble falling asleep once awake...

Anyone else have trouble falling back asleep after waking up? Ie. Usually if I have had +4.5 hrs of sleep, my mind or body wakes up to use the bathroom. Then I find I cannot fall back asleep. For the most part I'm awake the rest of the day. Rarely, I'll occupy my mind for a couple of hours until I exhaust myself to sleep, time permitting before the day begins with familial duties, of course. For the remainder of the day, I'm in a zombie state being mentally and physically exhausted.