The most common and most likely answer to this crossword clue is the 6 plus 2 letter word FOLLOW UP
I've seen this crossword clue in The Daily Telegraph
F
O
L
L
O
W
U
P
Buddy explains!
The straight part
We know that "Subsequent examination" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case subsequent examination = follow up.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FOLLOW UP mean?
FOLLOW UP noun- A subsidiary action taken in response to an event.
- A posted message on a newsgroup, etc. in reply to a previous one.
- A shot on goal directly following another that has been saved.
- The revisiting of a patient in ambulatory care.