There is a huge calcium thread on the products section. Look there as a start.A lot of people with D predominant IBS have found relief with calcium. If you're C, it'll make it worse (although I'me guessing you're not). Personally, I have IBS that alternates between D and C so have to be careful but find a supplelement with a 2:1 calcium to magnesium ratio to work pretty well. I take 3 a day that add up to 100% of the RDA for both.nancy