I agree with Maplerock, more info is needed.
DoDMERB docs are not there just to sign off on the medical history form you submit to them. They are there to give you a physical exam. IF that doc found something than it was their responsibility to report it on your exam.
I am going to make the assumption since you said it was 3 yrs ago, that they are now doing their exit DoDMERB exam this yr for commissioning. DoDMERB exams are only valid for 2 years, thus, as rising seniors in college they will have another exam to make sure they are still qualified for duty.
My advice is if this is a true worry get your medical records in order now.
It is rare, but there is a poster here that went to USAFA (hornetguy). He was pilot qualified when he commissioned. However, he was given an elite slot after commissioning to get his Ph.D through Rand (3 yrs), with a follow on to pilot training. During those 3 yrs., the exam process changed. He arrived at UPT, took another exam, and they DQd him due to the new regulations. He has no real problems with his eyes, and in the corporate world nobody would have given a 2nd notice. HOWEVER, not true with the AF. He even paid for specialist and fought it to the highest level, but to no avail. Hornet is now happily living life as a civilian.
Just saying.
OBTW, I don't know which branch or what career field your child wants, but I can tell you the exams in the AF do not ever end. If you go rated, you do an annual exam. They rotate between what is called the short (DoDMERB) and long (FAA). IE. In 2017 you take the short. (45 min exam). In 2018 you take the long (2+ hrs). 2019 you take the short again, and so on and so forth until you leave the service, at which point you do another exam for disability aspects!