Yes the bones he gets loose stool from are the marrow bones. The bones I give him that is butchered of beef or other animal he is completely fine on. Everything he gets has bones and organs in them. I buy ground meat that has bones and organs in them and I also buy chunks that have meat on the bone. I make it a point to buy beef liver, beef heart, beef kidney, turkey hearts, lamb heats, and some of the ground stuff includes tripe. The ground stuff is already well balanced to what a dog needs but I rotate between meat chunks, to ground meat, and to organs.