In the schooling BOOK I the MD explains food and the prune has an toxin that the stomach identifies and proceeds to expell from the body as fast as possible! I learned this must be the reason few people ever liked prunes as children. The older very ill person that uses them to remove their daily foods, becomes use to the poison. By poison, I mean a substance the body does not want. Just like Epsom Salts, so it forces the bowles to flush.