Get down to cases informal
To start working on something seriously or determinedly; to start doing what needs to be done
Hey everyone! Break time is over. Let's get down to cases!
There are some issues in our project plan, let's meet and get down to cases together, shall we?
Enthusiasm and perseverance
To despise or make determined attempts less strong
To make something beginning or happenning, especially an acitivity, event or a series of events
To concentrate on attaining a particular goal or award.
The verb "get" should be conjugated according to its tense.
The origin of this expression is not clear.
If someone has a cast iron stomach, they have a strong stomach that can digest unusual food and even bad food without being ill.
Jimmy must have a cast-iron stomach, when he drank milk with lime juice and felt perfectly fine afterward.