A childhood belief about weeing and pooing

when I was kid, I once got the idea that anything called a "poison" was inevitably fatal if you ate or drank it, no matter how small the amount you had consumed. And I thought furthermore that any poison would make you die exactly three days after you ate or drank it. Then one time my mother told me that you need to poop every day, because poop is poison and you need to get it out of your system. So I was terrified the first time after that when I went a day without pooping. I was sure that I would die three days later. So on the third day after that day I didn't poop, I was secretly preparing to lay me down to die. It didn't seem to matter that I HAD pooped on the two days in between.