There are multiple types of in patient facilities. Some allow you to come and go, use computers, have visitors. Others require you to turn in all of your electronics, you don't get them back until you check out and you aren't allowed to leave the floor because you are locked in. Some are in between -- you can have limited access to computers and phones and visitors at times but can't leave. Without knowing which kind he is in it's not possible to decide if he's intentionally ignoring you or if he's not able to contact you. But. If being on the internet or phone is causing him stress they will ban him from it regardless of what kind of program he is in. That can lead to erratic contact with the outside world.
They are also a ton of different lengths of times he could be in for. Could be a few days, could be a few months. There is no way to know until he is released. So you might be facing no contact or erratic contact for an extended amount of time. And if he is allowed to contact you and it raises his stress level (regardless of why) chances are they won't let him contact you again.
Hope that helps...