spew (one's) guts (out)
1. slang To speak truthfully and share everything one knows about something, especially a sensitive issue or a wrong one has committed. OK, spew your guts—I want to hear whatever you kids are plotting back there. I'm sorry, I didn't mean to just spew my guts out like that. I just haven't had anyone to talk to about what happened.
2. slang To vomit violently and lengthily. I've been spewing my guts all morning, so, no, I don't think I'll be in to work today. My friends got me so drunk on my 21st birthday that I spent the whole next day spewing my guts out.
spew one's guts (out)
1. Sl. to empty one's stomach; to vomit. Fred is spewing his guts out because of that lousy fish you served. He's spewing his guts because he has the flu.
2. Sl. to tell everything that one knows; to confess everything. (Underworld.) Lefty was sitting there in the police station spewing his guts out about the bank job. If he really is spewing his guts, the mob will cancel his Christmas.