allocation of basis on inservice distribution

[M Norton]

2-physician practice has a profit sharing plan.

One doctor took out a loan in excess of $50K.

So the excess on the loan has to be reported as a distribution, plus he has to pay it back.

That creates basis in the plan.

If the doctor takes an inservice distribution as allowed (now) by the plan, how is the basis allocated?

Can he choose to take out the basis money first?

Does it have to be prorated?

Thanks!