Fibers cannot be burned, so your intestants will work harder because they want to burn everything. This makes the poo less solid. But only if you have enough liquids in your body. They make poo hard when you're not drinking enough.
Whenever you have hameroids for example you get fibers from the doctor to make poo less solid. But they always tell you to drink enough water with it.
You'd need 2 to 3 liters of water per day.
Grok goes full nazi and Pentagon thinks "ooh we should hire it!"