Colloidal Silver is a great aid to healing, parasite killing, and disease killing - both bacterial and viral. When these happen, they cause adjustments in your body including digestive and elimination adjustments. Constipation is only one of many potential detox reactions one may experience when they change anything in their diet for the better. constipation is just the first one you noticed :) Detox is usually minor, temorary, and long term beneficial. You definitely want to treat the symptoms in the short term with constipation. There are probably other things you need to change in your diet and lifestyle to address the constipation. Over the long term Colloidal Silver alone won't give you problems - only benefits if used properly. If the detox gets uncomfortable, stop taking the CS temporarilly and then start back with a reduced amout. Increase it gradually and soon you'll be free of the reaction.
BTW, I just looked up again to make sure that I remembered correctly and Dr. Wallach, of "Dead Doctors Don't Lie", spends almost 2 pages of his book singing the praises of Colloidal Silver . It's an essential trace mineral as far as he is concerned. It's one of his 90 essential trace minerals that he says everyone should supplement their diet with daily.