How is a tradesperson's shit different to anyone else's?
All I know about tradesmen is that they usually need a van for the extra payload.
And no, I don't poo at work either!
Entirely your choice, but lots of people need/find it comfortable to use workplace toilets to poo in – and they aren’t wrong/weird/unreasonable/weak/disgusting in any way.
Do they think he should just hold it and/or spend the rest of his working day mincing around with tightly clenched buttocks?
Grim – like a special secret tradesmen’s version of the Lambeth Walk - with the chicken arm-movements and everything 
pooing not poking
I am NOT in favour of workmen poking anything
When it’s reached the poking stage, it’s usually too late to do anything but make a sprint for the nearest toilet and hope.
That would be a royal flush.
The smell is always at its very worst when it's crowning.