The 1970s Franken Berry Cereal Accidentally Gave Kids Pink Franken Poops

That’s according to Atlas Obscura. General Mills introduced its monster cereals (also including Count Chocula) in 1971, with the strawberry variety colored with Red Dye Nos. 2 and 3, a combination that had harmless but worrisome-looking consequences come toilet time:

Doctors ran all kinds of tests before they finally hit on the potential culprit. “Further questioning of the mother revealed that the child had eaten a bowl of Franken Berry cereal 2 days and 1 day prior to admission,” attending physician John V. Payne wrote in a case study later published in Pediatrics.

After letting the boy’s digestive system clear itself, they set out to test this new hypothesis, giving him four entire bowls of Franken Berry. Sure enough, he pooped pink again. “The stool had no abnormal odor, but looked like strawberry ice cream,” wrote Dr. Payne. They sent the kid home—where the mother found his sister also pooping pink.

Red No. 2 was banned in 1976 and so General Mills eventually swapped out the dyes. But not before enough ER visits that the existence of “Franken Berry Stool” had made its way into the annals of medicine.