Surprisingly, this is an often-asked strange question. Those asking are really wondering if BBQ charcoal can be used for water purification or medicine.
Charcoal manufacturers activate it by use of steam or hot air to erode its internal surface, which increases the outside surface area and its adsorption rate—the capacity to bind materials to a surface. Because of those adsorption abilities, charcoal has earned a reputation as a kind of bodily super-cleanser.
The medicinal use of activated charcoal is very specific, and no one should be eating the stuff by the spoonful. Or, you may have to do a quick dash to the ‘John’ (or so a ‘friend’ told me).
While there is no evidence of people dying from eating BBQ charcoal, we certainly do not recommend doing so. If you have health concerns, better consult with your health practitioner.