What does 血のしょんべん mean?


I'm trying to figure out what 血のションベン means. I understand the individual words
and literal meaning. So assuming it doesn't mean "bloods urine", what does
this mean?

Perhaps the full sentance is important in this case: 「私が最初に血のションベンを流した」

If you search for this phrase, just as is with the katakana 「ションベン」 you'll
find numerous hits online. I seem to always see it associated with 「流す」.

Here's another example, which I found online: 「女性にこんなこと言うのもあれなんやけどな、先生らの時代は
血のションベン（小便）だすまで勉強しろてようゆわれたもんやで」




血 means blood. しょんべん means pee. So it should be 血尿 meaning bloody urine. I
cannot think of other meanings.

