Post-op program (5)
I believe the answer is:
rehab
'post-op program' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rehab that I've seen before include "Treatment for, eg, addiction" , "Restoration to health after, eg, addiction (colloq.)" , "Health-restoring process" , "Treatment for addicts (abbrev.)" , "help with addiction" .)