mamaa
I'm in the 'wont be a minute, just popping to the loo' club, without adding any further detail... unlike my 5 yr old grandson who relishes announcing: 'ooh, I need a poo' whilst dashing off to the downstairs loo at speed. He does this every time even though he's told that such detail is not required😝.
My son at around the same age once answered my phone and told the caller "My mummy can't come to the phone at the moment because she's having a poo"!
I often suffer from constipation if I can't go at the moment the urge takes me, so I got into the habit of keeping a Sudoku puzzle book in the loo (now it's an old tablet and of course reading glasses) so it became habit to say "just going to do a Sudoku".
Now so "normal" with us it's even become a verb! 