Potty training while in Rome

We're taking our two years old to Rome in a couple weeks. He's getting fairly good with the potty training and we carry a potty with us and I've learnt how to ask in Italian at cafes if we can use the toilet. However, sometimes he needs to go with no notice. In the UK we just whip out the potty just on the pavement and then get rid of the wee in a bush or use nappy bags and anti bac wipes to dispose of anything else. My question is would this be acceptable in Rome? Is not, does anyone have any other recommendations for how to handle this? I'm happy to use nappies on public transport but would rather not go back to nappies for a whole week.