Right, it's flipping porridge (4)
I believe the answer is:
stir
'porridge' is the definition.
(both are slang terms for prison)
'right it's flipping' is the wordplay.
'right' becomes 'r' (common abbreviation).
'flipping' shows that the letters should be reversed in order.
'r'+'its'='rits'
'rits' back-to-front is 'STIR'.
(Other definitions for stir that I've seen before include "Mix the ingredients" , "cooler" , "College" , "Get moving" , "Bustle, activity" .)