Holding in Bowels...

Ok I have held in my bowels since as long as I can remember, im 25 now, and stopped a couple years ago when I became severely Ill, Could this be a cause of my health problems? I have had bad ADHD since birth and tested high with mercury. I tried probiotics which didnt seem to do jack. Only thing that makes me feel decent is avoiding certain foods and taking liquid magnesium. Sweating makes me feel good and gives me energy usually...