One American slang for toilet that I've never liked was "the John."
Military call it "the head."
I've pleasure to be member in this group
American Slang does not use "the loo"
Things like :
The potty (for kids)
The Crapper (for the man who invented it)
The porcelin God (When you are drunk, on your knees in front of it)
The lav (short for lavatory)
hello how are you
my name is fouad