Do we have any rights protecting us from someone knowingly running up debts ahead of bankruptcy?

It depends. First you need to learn whether the son's debts can even be included in the parents' bankruptcy case. If so, you will have to file an objection to discharge, and then prove that these clients entered into this debt knowing that they would be filing bankruptcy. Generally, any debt entered into during the six months prior to opening a bankruptcy case is suspect. A decent attorney should be able to establish your case. I wouldn't do it alone, though. You should hire a local attorney to represent you.

I assume that the parents signed that they would be financially responsible for their adult son's bills (or else why would it matter that they are filing bankruptcy). Read the paperwork that they signed, does it say that both the parents and the adult son are responsible for the bills? I can't imagine any lawyer would write an agreement that would exclude the adult son from liability (but you might have used a big name firm that has recent graduates do all the work and most of that work is just garbage). Unless your agreement specifically excludes the adult son from liability,then he's still liable despite the parent's bankruptcy. There is a law that prevents running up bills for luxuries before filing bankruptcy, most medical bills aren't luxuries but elective procedures and cosmetic surgery could certainly be luxuries.

Once someone is over 18 they are legally responsible for paying their own medical debts according to state law. If you work for a medical provider, you should know the state laws regarding this responsibility. Bankruptcy law has prohibitions under 11 USC sec 523 that address running up debt before filing but unless the medical debt was for a voluntary procedure, such as cosmetic surgery, it is unlikely that the court would deny a discharge of this debt. In order to make a claim like this, your employer would need to file an adversary proceeding in the bankruptcy within the deadline established by bankruptcy laws.

Unfortunately yes. The 20 year old is liable for his or her own debts. Majority in Colorado is 18 years of age.

Only minor children are included in a parent's bankruptcy. If the 20 year old incurred the debt you can go after him.