The word "gut" can have several meanings depending on its context.
1) It is a slang term for stomach or intestines, as in "I feel something bad in my gut."
2) It can also refer to one's instinctive intuition or inner feelings about something, as in "I had a gut feeling that it was the right thing to do."
3) In some regions of England and Ireland, "gut" is used as an exclamation of surprise or disbelief. For example: "Gut! I didn't know that!"