When you take 600 mg of calcium about 40 % does make it to the bones and the rest is gotten rid of in our waste. This is the part that may help some with diarrhea because calcium carbonate has the ability to soak up excess bile and water in the intestines and you have this usually if you have diarrhea so by doing that it can help to form the BM's. So by taking calcium at regular intervals throughout the day it gives the body the ability to rid it of the excess fluids.