Doctor, wise man accommodating fool (7)
I believe the answer is:
massage
'doctor' is the definition.
(both can mean to manipulate figures or information)
'wise man accommodating fool' is the wordplay.
'wise man' becomes 'mage' (I've seen this before).
'accommodating' means one lot of letters goes inside another.
'fool' becomes 'ass' (ass is a kind of fool).
'mage' going around 'ass' is 'MASSAGE'.
(Other definitions for massage that I've seen before include "Manipulate to get better results" , "Relaxing manipulation" , "Manipulate the muscles" , "See 10" , "Manipulation of the muscles" .)