I’m considering signing up for a sort of certification program that culminates in an all-day, competitive examination. And one of the first question that comes to mind is . . . what if I need to go to the bathroom? Folks who have taken CPA exams, bar exams and the like, did you plan ahead with, what, only light meals the day beforehand and very little water the morning of? I imagine if you were sitting for a six hour exam, chugging several cups of coffee that morning, after a huge spaghetti dinner the night before, might be a bad idea.
That’s why janitors are equipped with mops. Pee proudly, Kox, pee proudly.
(No, people writing the tests are not expected to hold it all day long.)
Along the same lines as Muffin, it would be ridiculous to demand that many people not go to the bathroom during quite long tests. In most situations, the worst restriction is that only one person at a time will be allowed out.
Then again, maybe there are some particularly obnoxious people who demand that test takers not go to the bathroom. Aside from situations like military training (when similating a situation where going to the bathroom could give away your position etc) it’s just ridiculous not to allow bathroom trips on a long test.
You could ask school staff what the rules are during the long test.
I’m sure that it’s allowed, I just want to minimize that time as much as possible. Competitive test, you know.
Then this ( David Sedaris on The Late Show - YouTube ) is for you.
The Virginia bar exam requires test-takers to wear “courtroom attire,” but to minimize the noise of footsteps going to and from the bathroom, we were also obliged to wear sneakers. We all looked like Chevy Chase or Ted Allen from Chopped.
When I took the CISSP exam - scheduled for 6 hours - bathroom breaks were allowed. We test takers had to be escorted to the bathroom by a proctor. Check the rules of the exam, or the place where you’ll take it. If the rules are unreasonable, maybe that’s not a good certification to have. If you need frequent or long bathroom breaks, plan your time carefully, or pre-arrange something with the testing organization. I’d love to see the testing-industrial complex taken down a notch or two via the ADA.
My CISSP experience was very similar to Typo Knig’s except we weren’t followed to the toilets. We were in a university building on a Saturday, the guard on the door made sure test-takers and proctors were the only people in the building. You could also request a break to go to the back of the exam room for a quiet snack or drink. I finished (and passed) in a little over two hours so breaks weren’t an issue for me.
Long ago I took the GRE. I arrived early, and sat quietly preparing myself mentally. Another test taker was talking about how the results of this test would determine how the rest of his life would proceed. He was nervous, pacing, and rambling.
Midway through the first section, nervous dude had to go to the bathroom. He was gone “too long” for a simple pee break. I finished the section just as he raced in and resumed. When the time keeper said, “Stop”, he was flustered.
Maybe thirty minutes later he needed another bathroom break. Over the course of the day he needed several more. I felt really bad for he dude.
I’s actually suggest the opposite, on the advice of test prep teachers. Use your bathroom breaks. Your bladder may not need them, but your mind does.
The longest test I took was one to get out of nursing school (not the licensing one, that was actually pretty short.) It was several hours; I forget how many exactly. I did force myself to take a break. The set up was that they had a proctor walk you to the bathroom. There I took a few deep breaths, sang a verse of “With a Little Bit of Luck” (really, the proctor was trying hard not to laugh) and washed my hands and fingercombed my hair and redid the hair clip. Never actually used the toilet, 'cause I didn’t need to. But it was like pressing Refresh on my brain, and I went back in and finished the test more effectively than I could have without the break.
Time management is important, but include at least one Stand and Breathe break every hour or two in that time management.
But the very best piece of Big Test taking advice I got: Do *not *try to get a good’s night sleep before the exam. You won’t. Get a good night’s sleep the night *before *the night before the exam. If your exam is on Friday, forget about Thursday night. Get lots of sleep Wednesday night. Then your body is working on Full, and if you can’t sleep Thursday night, you’re only down a quarter tank and your adrenaline will carry you through the exam. And what most of us actually found was that getting rid of the pressure to sleep well Thursday night perversely allowed us to sleep well anyway! 
Yes, I agree with WhyNot about the “night before the night before” it really helps.
For the bathroom breaks, I think our six hour RN licencing exam (Canada) was a 3 in the morning 3 in the afternoon. I can hold a three hour need to pee standing on my head* but there was some kind of procedure in place for bathroom breaks. I think we could even have water and snacks with us. (I never thought I would say that exam is a fainting memory, but I guess after nearly 14 years it is. I mostly remember being outraged by one question on the exam and had to talk myself through not protesting.)
*Well not really.
Hear hear. I’ve taken very demanding four-hour actuarial exams, where every minute counted, and even so it would not have occurred to me to stint on bathroom breaks. (They were allowed, obviously.) The distraction of even a mild need-to-pee will cost you more than the two minutes it takes to get up and relieve yourself. And as you say, getting up brings ancillary benefits in helping to clear and refresh your mind.
I imagine that dehydrating and/or starving yourself to try to prevent the need for the bathroom would probably put you at a greater disadvantage than taking a 5 minute break - your brain won’t work so well if you’re under physical stress of that kind.
I first read this as “CPISS exam” and thought to myself, of course it allows bathroom breaks!
Presumably an actuarial exam would build in the expected number of bathroom trips to its time limit. 
How very… Virginia(?) of them. In Ohio it was shorts and a t shirt for me. The bar exam is given in old exhibit hall and courtroom attire would quickly become uncomfortable.
To answer the question, the Ohio bar exam is in reality a series of short exams over two and half days. So plenty of time to use the restroom when you finish a given section. Check to see the format for your test. It likely has opportunities for breaks.
During the morning session of the NY Bar Exam, I held it for as long as I could, then ran down the aisle to the bathrooms at the back, peed as quickly as my bladder would allow, and then ran back to my table. All I really wanted to accomplish was to take the pressure off so I could finish. When the session broke I had to go again, but that was OK, I was able to concentrate on the test enough to get through it. I didn’t have to go during the afternoon session.
Depends
No, no, I think you misunderstood…holding your pee IS the RN licensing exam. 3 hours gets you an RN. 9 hours gets you made Charge Nurse. 12 hours and you’re automatically qualified for ER. 
HA!
The NCLEX-RN has a maximum time of 6 hours. Bathroom breaks were allowed where I took it but you have to reauthenticate your identity by a fingerprint scanner. The woman who taught my licensing exam refresher course taught us a phrase guaranteed to get you a bathroom break no matter how reluctant someone is to allow you one, no matter the circumstances:
“I feel like I am about to have explosive diarrhea.”
I didn’t have to use the phrase as I was out in under an hour, but you never know when it will come in handy.
Four hours! That seems almost barbaric…and that was four-hour exams, plural?