Make an issue of something (4)
I believe the answer is:
emit
'make' is the definition.
The answer and definition can be both related to bodily activities as well as being verbs in their base form.
Maybe you can see an association between them that I don't see?
'an issue of something' is the wordplay.
'an issue of' becomes 'em' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'something' becomes 'it' (I've seen this in other clues).
'em'+'it'='EMIT'
Can you help me to learn more?
(Other definitions for emit that I've seen before include "Let out" , "Give off or discharge" , "Throw out" , "Exhale" , "Send forth" .)