How much spinach do i need to eat to change my poop color? i had like 5 spinach leaves and when i pooped, my poop was a dark tarry black color and it had red streaks in it too. this has never happened before when ive eaten spinach?

Black stool with red: I'm reluctant to attribute this to ingestion of spinach. Truly black, tarry stools are often seen with bleeding from the stomach or duodenum but red blood occurs with bleeding from the anus, rectum or colon. Black stools can be due to taking iron supplements or medications like peptobismol or kaopectate. See your MD for evaluation if stool appearance can't explained by iron pills,etc