Joko... you won't see anything in the bowl. The blockage will be either in the trap ("around the bend"), or further along the line.
Baby wipes; J-cloths; Disposable nappies....... are nearly always the problem. I don't think the blockage can be far from the bowl though, or the problem would show up downstairs in the shop toilet.
It may clear itself eventually, on its own. If not, the pan would have to be taken out so that the soil-pipe can be cleared. It wouldn't take a plumber very long to sort it.