The metals thing sounds very interesting and a possibility. Mostly, tho, I think whenever you stir things up but don't get them OUT Of you fast enough, the kidneys get stressed. :(
That's also what goes wrong with Liver Flushes - if you don't do colonics/colemas afterward, the toxins recirculate. That's the only way you can do "too many" Liver Flushes so that they harm you - doign them too frequently and/or not getting toxins out of you fast enough.