Stomach in general keeps hurting (6)
I believe the answer is:
aching
'hurting' is the definition.
('ache' can be a synonym of 'hurt')
'stomach in general keeps' is the wordplay.
'keeps' says the answer is hidden in the clue.
'ACHING' is hidden within 'stomach in general'.
(Other definitions for aching that I've seen before include "Suffering a dull persistent pain" , "Feeling pain" , "Painful" , "Sore" , "Yearning; in pain" .)