spill out (one's) guts

Translations
излить душу
After a few drinks, he started to spill out his guts about his problems.
После нескольких рюмок он начал изливать душу о своих проблемах.
Definitions
To reveal one's deepest thoughts, feelings, or secrets, often in a very honest or emotional way; to confess or share everything one knows about a situation.