A childhood belief about weeing and pooing

Once when I was a child, a business associate of my father's came to see him at this shop. That day the associate had his wife and their little girl with him. At one point the girl walked up to her mother and said, "Mommy, I've got to doodoo!" I was astounded, because I must have believed, as I've noticed others on this site have, that girls didn't doodoo. So later at school, I asked my best friend if girls doodoo. I hoped he'd know, since he had two sisters. But he seemed embarrassed and just said nothing. I didn't want to be overheard, but I was, by a girl I didn't trust. She walked up and said, "Are you stupid? Of course girls doodoo!" I wasn't ordinarily comfortable talking to her, but desperate to know, I asked her more. I don't remember the exact details of our conversation. But it continued with her acting as if I were stupid, but ended with her telling me that boys and girls are different only in how they pee, and that both doodoo the same. I wanted to believe, But since I didn't trust her, I ventured to go ask the teacher if she had told me the truth. I told the teacher, "Valerie told me that girls doodoo just the same as boys. Is that true?" The teacher's baffling response was "Only in extreme cases." Did she somehow misunderstand my question? If so, what did she think I was asking? Or was she just somehow cruelly playing with me in a way no teacher should? In any event, I puzzled for years afterwards, thinking girls doodooed much more seldom that boys and wondering what were the extreme cases in which they would doo it.