I enjoy a fatty meats as much as anyone but giving up veggies entirely even though it objectively hurts ones ability to go to the toilet comfortably turns this into farce for me.
Fiber. Most all-meat diets suggest taking fiber or psyllium husk supplements for this very reason.
Good for them then. I'm not sure why this is better than just eating vegetables in some capacity but that's not for me to judge I guess.