It means to hate someone so deeply. The guts is basically stomach area and as you may know we get all sort of movement in stomach area linked to emotional state of mind. You can also say “I don’t have guts to do something “ meaning you can not stomach some actions or be brave enough….or quite the opposite “ he has some guts” if someone is being brave Hope this helps

it just means to hate some one

To hate that person a lot.

to dislike / to loathe / to despise someone profoundly.

Yes it means to hate someone but with more emphasis so to hate everything about someone and be unable to see any redeeming qualities in the person