PC Bib Langenscheidt Fachwörterbuch Medizin:

"Bandscheibe f (Anat) intervertebral disk (disc), IVD, intervertebral cartilage"

and the use of "du", I think something less formal and perhaps more general than "intervertebral disc" might be called for - perhaps something along the lines of "is your back in good shape?" Certaily the lay person would know what a "dis" is - "slipped disc" etc - but I think "Bandscheibe" is being used more generally and less specifically here.