Why is it that everytime i drink prune juice for constipation i have to run to the bathroom with horrible painful diarreah and gas?

Osmotic laxative : Prune naturally contains sorbitol which has a mild laxative action. Prunes also contain large amounts of phenolic compounds (e.g. Neochlorogenic and chlorogenic acids), which are also though to have laxative properties. Once the cause of your constipation is diagnosed, a non-osmotic laxative may work better for you. Or simply eat a prune or two.