Obscene magazine shows medical procedure (5)
I believe the answer is:
enema
'medical procedure' is the definition.
(I've seen this before)
'obscene magazine shows' is the wordplay.
'shows' indicates a hidden word.
'ENEMA' is hidden in the letters of 'obscene magazine'.
(Other definitions for enema that I've seen before include "treatment by rear entrance" , "process to ensure evacuation" , "Bowel evacuator" , "Rectal medicine" , "Fluid injected rectally" .)