Gastrointestinal

• Activated charcoal can have gastrointestinal effects when taken. Contrary to popular belief, activated charcoal has not been found to actually help the opposite problem of diarrhea. Studies show that about 13 to 30 percent of people experienced side effects of nausea and vomiting, as well as constipation, according to Drugs.com. Other gastrointestinal side effects of activated charcoal include blackened stools and a perforated gastrointestinal tract, although this is less common.
  
  

Metabolic

• The metabolic side effects of using activated charcoal treatments are electrolyte imbalances, dehydration and shock. While these are serious conditions, they can be replenished and monitored. However, the metabolic effects of using activated charcoal are usually only present when there is sorbitol in the treatment.
  
  

Respiratory

• The respiratory side effects of using activated charcoal can include bronchiolitis obliterans, which is an inflammation of the lungs that are plugged with connective tissue. Another effect is empyema, which is an infection where pus in the cavity between the lungs and the membrane collects. Adult Respiratory Distress Syndrome can also be present, which in the case of this treatment can happen when charcoal accidentally gets directly into the lungs.
  
  

Administration

• Because some of the side effects of activated charcoal treatments can be very serious and dangerous, it is important to check with your doctor before using this treatment. You should only be using this treatment if it is prescribed by a doctor, and you should follow the instructions closely. If you experience any of the side effects mentioned, you should contact your doctor or go to the emergency room depending on how serious it is.