I was going to say calc-c, glad to see GM recommended it. In my observations, constipation many times can come from poor calcium assimilation. Calc-c can improve this. Also, those I know with chronic fatigue syndrome have low levels of calcium in their blood, even when taking calcium supplements. So I would say take the calc-c 200c as GM suggested and also take a good, pure calcium supplement, which needs to be taken around the clock for your body to best absorb. 1500 - 2000mg per day. (i.e. 500mg 3-4 times a day)