When purchasing colloidal silver, always make sure it is NOT ionic silver because this is much less beneficial to health. In chemical terms, a silver ion is an atom which lacks one electron. The silver ions are produced through electrolysis and can be regarded as "decomposed" silver. These products are often designated as "electro colloids", which scientifically speaking is incorrect.
Ionic silver is either clear like water or slightly yellow. It is different to colloidal silver. Genuine colloidal silver is made from small silver nanoparticles. The atoms are complete, therefore they don't have any electrical charge and so cannot bind with other elements. Colloidal silver particles can be excreted again from the body, therefore they do not accumulate.
These small particles of real colloidal silver are mostly resorbed in the mouth, stomach and intestines. This is why it's important to use highly-concentrated colloidal silver that will make it to the lower intestinal tract and destroy unwanted bacteria there. In its ionic form, silver seeks a bonding partner (usually a chloride) and is no longer able to kill off bacteria.
It is a complicated and difficult process to produce real colloidal silver. It's therefore no secret why most manufacturers decide to make ionic silver instead and call it colloidal silver. Luckily, buyers increasingly know the difference: if it looks like water, then it is ionic silver rather than genuine silver colloid.