The most common and most likely answer to this crossword clue is the 6 letter word BARFED
I've seen this crossword clue in The Guardian
B
A
R
F
E
D
Buddy explains!
The straight part
We know that "brought it all up" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case brought it all up = barfed.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 BARFED mean?
BARFED verb- To vomit.
- Of a system: to fail.