Conversation so far:
what is the second toilet in the bathroom for
The bidet is often a basin that is situated close to the toilet in the bathroom, and it is used to clean yourself after using the toilet.
what is a bidet used to clean
Bidets are primarily used to wash and clean the genitalia, perineum, inner buttocks, and anus.

Question: where is use common
Self-contained rewrite: where is use of a bidet common