There may be several reasons why a cat keeps meowing in the bathroom:
1. Physiological needs: If the litter box is not clean or is not cleaned in time, the cat may frequently go to the bathroom to meow due to physiological needs.

2. Attracting attention: If a cat feels lonely or doesn't get enough attention, it may meow to attract its owner's attention. In this case, spend more time with it or use interactive toys to distract it.
3. Curiosity: A cat's curiosity about the bathroom may also cause it to frequently go to the bathroom and meow. You can install a cat door or take other measures to ensure that the bathroom is safe for the cat.