Red cloud like watery mixture that spreads, or red goo & noodles out its "hindquarters"?
If its a thin liquid that clouded kind of like the Alk part of B-ionic (or your favorite 2 part), I'd do a water change and get it out.
At this point, it will most likely die slowly over a few months if it released most of its weight in toxins. Hard for them to regenerate their insides, as there isn't much to them (try dissecting one, real boring class, almost like the earthworm dissection in 5th grade).
If it in your 180 i see there, less to worry about due to volume, but still. It really depends on your cuke / toxicity. Also, if it spits it guts out, just pull the stuff out so it doesn't rot. Again, this can mean it isn't healthy and will die over a couple months.
I had a yellow cuke eviscerate and die overnite in a 29 gallon. Threw him out, added some carbon, and did 30-40%. Fortunately no big deal. I'd keep a very close eye. Good luck.