Hi fizzy.
Is it the first appt with the consultant or the dietician/anathatist/psychologist?
If its the consultant - they'll talk to you about your eating habits, explain all procedures to you and then advise which is best for you. Normally if you're a quantity eater, the band is best. If (like me) sweets and biscuits are your downfall, bypass is better.
If its the dietician, anathatist,psychologist - you'll see each person and they'll discuss your eating habits, your medical history, check weight and height, BP etc. Can take a few hours so be prepared!
Have to say tho - St Richards are fantastic and you couldn't be in better hands!