ah...lol? I never seen this bug so far to be honest. Try to reinstall your drivers and also reinstall the game maybe it should fix the error.

When blood falls on the floor it goes into this square with stripes pattern when it hits the floor.

All i can think of is to use

/opt bloodstains 0
then
/opt bloodstains 1

turning it off and on again ;)

Sup fella

Your GPU can't handle the physics calculations asked by the engine to make the blood fluid while on the floor. Go to your settings and set the video quality to the lowest possible, then check if it gets any better, go growing in quality untill you find what quality your GPU can't handle.

If this happens in all settings or you've seen fluid blod working in the past all you need to do is reinstall your Graphic Card driver (if you have nvidia don't forget to install the newest physics package and DirectX).

PS: I'm assuming you have the 'fluid blood' setting on, check it off, restart the game and check it on again.

IIIsnaneEEE i can run toribash at max and it works fine but the only problem is the blood

In this case it's just a fluid blood problem, if you ever saw fluid blood in your PC then just reinstall TB, otherwise you may want to check out your video card. My Nvidia got crazy one time when I forgot to update drivers for like 6 months.

I got a Mac

Reinstall TB. That option seems to help with most bugs.