Diary of a Spider

Diya loves to read books. So, I bought a new one for her - The Diary of a Spider. As soon as I told her about the new book, she wanted me to sit down by her and start reading.

But as soon as I read her the name of the book she looked utterly shocked. She said I said a "bad word"! And she won't hear the story at all, especially if it is related to "potty".

I was stunned! What did I do?

I understood what happened a few seconds later. It seems she had recently learnt the word "Diarrhea", but was still struggling with the pronunciation. :)

Now when and where did she learn that word from?