That is indeed a mystery. My first suspicion would be some form of Candida. Activated charcoal is often used as an adjuvant treatment for Candida because it absorbs the toxins that are released by dying Candida cells. On the other hand, though Calcium D Glucarate is not ordinarily listed as a treatment for Candida, it helps the body eliminate toxins and so it might be that both of their actions provide temporary relief due to their actions on toxins.
Colloidal silver coupled with probiotics and plant derived trace minerals might be a good idea. Even if it is not Candida, such a combination has been effective for many conditions - and would be particularly good for Candida and low energy.