Doo Doo
It is a phrase used imn much of Pennsylvania.
Meanings include 
1. The act of not telling someone something they want to know.
2.To not continue the specific convo.
3.To Change the topic or conversation.
4.When said fast can show happiness.
5.When upset will be said under breath, muttered.

Hey what happened to you and your girlfriend? Response :Doo Doo