Thank you for your question this evening.
The answer is it depends on what the outcome of the case is (it sounds like this is a recent occurance, but if I am wrong in my assumption, please let me know).
In Illinois, you are eligible to expunge most non-traffic misdemeanor offenses from your criminal record, as long as you do not have any convictions.
If you are placed on court supervision, receive a deferred prosecution, first offender probation, or your case is dismissed, or you are found not guilty at trial, you may be eligible to have your criminal arrest record expunged.
If you are placed on probation, conditional discharge, receive a Judgment of Conviction, or are sentenced to the Illinois Department of Corrections for any criminal offense (not likely for something so minor), you are generally not eligible to have your criminal record expunged.
Even if you are not eligible to have your records expunged, you may still be eligible to have your record sealed. If your record is sealed, only a court order can unseal the record.
If this is a first offense, what I would expect is if you are found guilty, that you will receive a sentence of "supervision." Court supervision is, essentially, a deferment by the court of entry of a judgment of conviction. That means on a job application, if you successfully complete the terms of supervision, if asked if you have a conviction, you can say "no." And, as previously noted above, supervision, because it is not a conviction is eligible for expungement.
Please note --under current Illinois law, an expungement cannot be filed until 5 years after disposition of your case. So, for example, if your sentence is 1 year of supervision, you would not be able to seek an expungement until 6 years has passed.
Also, your medical school background check will likely require you (if it's anything like the character and fitness check that prospective lawyers go through) to reveal any and all criminal offenses -even those that were sealed or expunged.