You should expect your vet to look over the exterior of the snake, (checking for mites, ticks, retained sheds, etc.); s/he then will probably check the snake's mouth (for sores, missing/infected teeth and gums, mouthrot, etc.); and most of all, they will probably want a fecal sample to check for worms and other parasites. If this isn't too late, try to collect a fresh stool before going to the vet. Store in the fridge (NOT the freezer) until you leave for the appointment. Good luck, and I hope this helps!