Nikki, is he being sent to attend Field Medical Training Battalion at Camp Lejeune?  If so, that's an eight-week training program that nearly every corpsman goes through eventually.  Read this to learn about FMTB:  "What is Field Medical Training Battalion?"   Going through FMTB does NOT mean that he would stay on at Camp Lejeune afterward.

If he says that he is headed to a hospital in Virginia, then he is likely headed to Naval Medical Center Portsmouth (Virginia) immediately after completing FMTB.  

Nikki,
My son is a corpsman who was stationed with the Marines at Camp Pendleton in California. After he finished his A School in San Antonio, he served at a hospital in Jacksonville, FL. Unfortunately, he was not that happy in Florida. He is a California native, so he asked to go through FMTB school. He also obtained his FMF while being stationed with the Marines for over three years. He also was deployed with the Marines to Okinawa, Japan, and Korea. He loved his time with the Marines.
He is now in C School for Preventative Medicine in San Antonio. He has told me that he would have no problem going back to Camp Pendleton.
Do not worry. The Marines love their corpsman, and they protect them.
I worried the most when he was deployed, but everyone came back safely.

My son went through the training and ended up with a Seabee unit. Not everyone goes with the Marines.