High protein acts as a natural diuretic and since the body needs fluid to aid the digestion process your waste material is probably hard prior to the last part of the digestion process where fluid is sucked out of your excrement thus making it near impossible for the body to move the waste product along the digestive process-------- poos should be solid in texture but still moist to touch so if you are to solid before the last part of this process you will get all stuck and bogged !!!!