Htydjtk

I can't believe I'm needing to even ask this question

You didn't.

A junior coworker of mine (lets call him Hans) is pretty immature. Hans will spend over an hour at a time going to the bathroom every day

Not sure what going to the bathroom has to do with maturity? Perhaps Hans has a medical condition. What business is that of yours? Is Hans really the immature one?

And if you're wondering, yes, I timed it.

Stop doing that, right now.

Now I notice it every day when he's in the bathroom.

Mind your own business, and focus on your own work.

He also usually doesn't finish his work on time.

Unless you're Hans's manager, this is — once again — none of your business.

I'm now wondering if I should bring it up

No.

I've casually mentioned to Hans before how he should try to limit his breaks (without mentioning I know how much time he spends in the bathroom), but he didn't really pay attention to me.

Of course he didn't. You're lucky he didn't report you for harassment. Don't do that again.

Is it appropriate for me to be blunt and bring this up to him?

No.

One on hand, it would be better if he heard it from me before he got chewed out from my manager.

No. Only your manager should be discussing things like this with him.

But on the other hand, I really don't want to have this awkward conversation with him.

Good, don't.

What is the professional thing to do in this circumstance?

Stopping literally everything you're doing about it at the moment.

Get on with your work.

Your manager is (I hope) trained on how to have these embarrassing conversations and how to suggest a change in behavior or accommodate a medical situation. You are not trained (imagine if he suddenly revealed medical details to you) and have no authority to offer accommodations or demand a change of ways. Leave the managing to the manager and cheer up your coworker afterwards if he is left upset by the conversation.

You've mentioned it once. Chances are others have too. At this point, the situation is not going to change due to coworker nudges.

You have already warned him and it appears he has ignored you.

If you warn him again, then the manager talks to him - he may associate that as your fault and be annoyed at you.

I had a similar situation about a more serious issue and warned a colleague ... who did not listen, eventually management fired him...

You have been a friend and told him, stay out of it now.

Maybe give him a friendly heads up that you overheard the manager talking about it, but keep the emphasis on friendly. Generally speaking, the bathroom habits of your colleagues are none of your business so put the emphasis on him being away from the desk without bringing up the toilet.

It's worth bearing in mind that there are medical conditions that require spending an above-average amount of time on the toilet, and the people who suffer from them generally don't want to talk about them.

Whatever you do, don't let him know that you've been timing his breaks. That'll just make you come over like a creepy stalker and you could find yourself being the one on the receiving end of a warning over it.

First, this is potentially an issue with ADA, Unruh or your jurisdiction's equivalent laws that protect persons with disabilities or medical conditions. As such, anything remotely related to medical or disabilities must be handled in compliance with relevant laws and with the utmost sensitivity.

What's more, there are things you may not know, that you should not know, or may not be allowed to know. If you had a horrible injury or disease that required you to spend an hour a day giving yourself injections or dealing with a colostomy bag or doing infusion or dialysis or something, you might be really private about it and really wouldn't want your privacy invaded by your coworkers. So pause to realize that invading his privacy, itself, is a grave violence against him.

It is possible that the employee has already disclosed this to HR, and the issue is understood by them, and you didn't get the memo because you don't have any right.

On the other hand, maybe he's in there playing Candy Crush, but ADA is such a legal minefield that you must assume worst case.

So let's be clear on this point: the topic of bathroom activity is 110% totally out of bounds here. You cannot raise his absence issue in any way which could possibly relate to his use of the bathroom. Since you believe you know where he goes, do not ask him where he goes. That can come to no good.

That said, two things are fair game.

First, you can state concern about his frequent absences, assuming that you have no earthly idea where he goes. In fact, telling him "the boss was looking for you, and he's annoyed to not find you" is a decent "watching your bro's back" thing that I recommend.

Second, you can use all the standard/normal methods to deal with the anonymous individual hogging the stall. General protocols are first, immediately make your presence known by pulling on the locked door audibly (but don't overpower a stall's latch, obviously). Then after about 10 seconds, knock; that puts the person on notice to wrap up. Proper response is "just a sec" and quick wrap-up. Then every minute or so, knock more firmly and say "Come on!" Or other statements expressing urgency with ever-increasing obnoxiousness. Nobody has a right to tie up a stall for 20 minutes, so it's "gloves off" when dealing through the door with this anonymous person. If there's no response after 5 minutes, presume medical emergency and get a supervisor with a key.

This is ultimately a "nunya" situation; nunya funkin' business. Is this really how you wish to learn about a co-worker's private medical condition of which you have no right to know about?

If you have an issue with bathroom wait times then complain about bathroom wait times.

If you have an issue with working with someone who is never at their desk then complain that you can never find person xyz when you need them.

If this person is truly unaware that their hour-long bathroom breaks are causing an issue then they will be informed by the appropriate individual when the time comes. If they are already aware and they continue with the behavior then you should give them the benefit of the doubt and assume they need to do what they are doing.