Federal crime, federal probation violation DUI

He could go back to jail, he could be ordered into an inpatient facility at his costs or any myriad of other possiblilites. Please see to it that the person gets the best attorney who he can find and one that handles cases regularly in Federal court. You may want to contact a member of National Association of Criminal Defense Lawyers (NACDL) or their Maryland affiliate Maryland Criminal Defense Attorney's Association (MCDAA).

Good Luck

There are many options:
1. The court can modify his probation--e.g. he could be sent to inpatient/outpatient rehab, be ordered to serve a jail sanction, be ordered to take antabuse, etc.
2. The court can revoke his probation and send him to prison to serve his sentence.
3. Deny the motion to revoke.
Without knowing all the circumstances, please consult an attorney familiar with federal law in the jurisdiction you live. Good luck.

The advice given by the other attorneys to this question is sound - you should check with a lawyer who can answer the question in a way that's more appropriate to your circumstances and judge.

One additional though, though, is that you should try to talk to your probation officer. Especially in federal court, and, I think, especially in Maryland, your probation officer is a person who you need to be talking to and working with. Sometimes the probation officer has discretion to not file a violation and bring you in front of the judge. If you do go before the judge, having your probation officer on your side can be very valuable.

Some probation officers won't work with you, but some will. Ideally, in federal court, your probation officer should have the time to talk to you and work with you, at least more than a state probation officer would.

So, yes, definitely talk to a lawyer, but try to work with your probation officer, if possible, too.

Good luck!