How Long Can A Person Be Held In A Psychiatric Facility In Mo?

Not sure if this is the right place to ask this, or if I'm going to phrase it correctly, so I apologize in advance...

So the gist of my situation, my wife checked herself into the hospital last Thursday evening. Due to issues she was having with the medicine she was on. I was at work at the time.

When she checked herself in, they didn't really give her any information on how long she was going to be held. They also didn't ask her to fill out anything regarding emergency contact information, or anything allowing them to speak to me regarding her medical care.

Flash forward a couple of days, my wife is now having issues with being harassed by two male patients, she's complained about it, but was informed that if she continued to complain about it then they would be transferring her to where they keep the violent patients.

No one has attempted to contact me regarding my wife's care, and when I've visited I've gotten very vague answers. I just had her sign the medical release today allowing them to talk to me

My question is this. In the state of Missouri, at what point am I allowed to sign my wife out of psychiatric care, after she voluntarily checked herself in?