Trouble over sphincter, tender (7)
I believe the answer is:
adoring
'tender' is the definition.
(thesaurus)
'trouble over sphincter' is the wordplay.
'trouble' becomes 'ado' (both can mean bother or commotion).
'over sphincter' becomes 'ring' (I am not sure about this - if you are sure you should believe this answer much more).
'ado'+'ring'='ADORING'
Can you help me to learn more?
(Other definitions for adoring that I've seen before include "Worshipping the loved one" , "Worshipping; admiring" , "Really getting into" , "Greatly loving" , "Loving deeply" .)