Sewer gets doctor in a pickle (5)
I believe the answer is:
drain
'sewer' is the definition.
(drain can mean a sewer)
'doctor in a pickle' is the wordplay.
'doctor' becomes 'dr' (abbreviation).
'pickle' indicates anagramming the letters (I've seen 'pickled' mean this (I've seen this in other clues)).
'in'+'a'='ina'
'ina' is an anagram of 'ain'.
'dr'+'ain'='DRAIN'
'gets' acts as a link.
(Other definitions for drain that I've seen before include "To empty (of fluid)" , "Empty of liquid" , "Gutter" , "Exhaust (of liquid)" , "Make weak" .)