have no stomach

not have the stomach (for something) also have no stomach (for something)

to not feel strong or brave enough to do something unpleasant  

The soldiers did not have the stomach for another fight.

Usage notes: sometimes used in the form not have the stomach to do something: 

I don't think I've got the stomach to argue with her again about money.

It pays to keep Kleenex around --especially If you don't have the stomach to watch somebody slobber all over this new hockey jersey.