Couple upset a Scottish hooligan? That takes guts! (7)

'that takes guts' is the definition.
(plural of duodenum, part of the small intestine)

'couple upset a scottish hooligan?' is the wordplay.
'couple' becomes 'duo' (synonyms).
'upset' says the letters should be written in reverse.
'scottish hooligan?' becomes 'ned' (Scottish term for a hooligan).
'a'+'ned'='aned'
'aned' reversed gives 'dena'.
'duo'+'dena'='DUODENA'