Guts= entrails "to hate someone's guts/ can't stand someone's guts" means to hate that person with all your heart and soul. Little kids often say this to each other in the playground once they understand that you can hurt someone with words as well as actions. Examples: 1. I hate your guts cos you pushed me off the swing. 2.That guy was such a real loser, that she hated his guts. 3.He hoped that his ex would rot in hell. He couldn't can't stand her guts!

More likely would be: "He dumped me for no reason. I hate his guts!" When you hate someone's guts, you hate them intensely - every part of them, including their insides - their "guts".