Salacious material that has stomachs turning (4)
I believe the answer is:
smut
'salacious material' is the definition.
(I've seen this before)
'stomachs turning' is the wordplay.
'stomachs' becomes 'tums' ('tum' can be a synonym of 'stomach').
'turning' is a reversal indicator.
'tums' written backwards gives 'SMUT'.
'that has' is the link.
(Other definitions for smut that I've seen before include "Bit of soot or dirty talk" , "Obscene word(s)" , "Obscene material" , "Indecent stuff" , "porn?" .)