Hm....I would have said, get rid of the bidet and have the entrance from the toilet side without a door, etc., but that wasn't the question :D The passage at the end could be 50-60cm and then I would probably put up a 70-80cm glass panel, although personally I find half-height masonry with glass on top much better. Dimension-wise that would probably be about like above at , that looks good and water also splashes out at 140 but that's not flooding. If you install a door you will always have a bit of water outside. Depending on how you do it, you could still retrofit a door if necessary, although from experience people never do that, but adapt to the circumstances, which I wouldn’t find difficult here.