What is the chance of a person being able to re-enlist if they are medically discharged?

Depends on your RE code. If waver-able, depends on if the military needs your skill set and how badly. Also depends on if you can find a recruiter who (is desperate) doesn't mind the extra paperwork associated with medical wavers. Basically, reenlistment with a medical issue is not likely but it can be done.

Slim. If the condition has been successfully treated, and waiverable, you will have to go through a medical board to get back in. But, I don't think your chances are very high.

How talk to a recruiter. You will get the best answers there

Slim to none, and probably leading more towards none since the US Military Medical Review Board deemed you physically unfit for continued military service. But, there are always loopholes and catches.