Fun story.
I'm flying north to Fort Collins, toward the Denver Class B airspace, when I'm suddenly cleared through the airspace without even asking. Outstanding!
Well, I literally cross the Class B boundary, and start to hit some turbulence and it hits me. I HAVE TO PEE! I apparently drank that last Dr. Pepper much too fast. I don't know how long I needed to pee without noticing, but I do know that this was pretty urgent.
"Its ok" I told myself, "I'm only about 40 minutes from Fort Collins, maybe less. I can do this."
5 minutes later, and a bunch of huge turbulent bursts later, I'm freaking out. I can't wait...I have to go now. Off to my left is JeffCo...but if I start asking for clearances and whatnot, there's no chance I'm going to make it down before I have a very bad accident.
I'm in pain....my thumb is hovering over the PTT, about to declare an emergency because I really felt this was a safety of flight issue....but then it occurs to me: I can't possibly be holding more than 12 ounces of pee, right?
I scramble for the empty Dr. Pepper can I just finished, aim very carefully so as not to cut my good stuff on the rim, and let it go.
And it went.
And it went.
And I was approaching 12 ounces, and started panicking. "What do I do now??"
Well, this particular Cherokee 180 has one of those awesomely functional 3 inch by 3 inch windows on the left side. I squeeze it off, and dump the contents out the window, careful not to spill any (the ash story was in my head, and I was very scared). I brought it back and continued.
Probably 2 cans worth later, I was finished. I had drifted off my assigned Altitude of I think 13,500ft but my heading was simply "west of I-40" (or east...can't remember). At this point, I found an interesting point of knowledge.
Pee freezes.
I had peecicles all the way down the left side of my Cherokee, and when I landed a little later, I had a nice puddle forming under the plane.
That's my fun story (probably the best "fun" story I have as a pilot). If you've ever been there, you know what I was feeling. If you haven't, don't get that far. It sucks.