Factose Intolerance (medical condition)
The condition brought about by the incomplete digestion of facts in guts normally accustomed to truthiness. People with Factose Intolerance, like Dr. Stephen T. Colbert, experience a number of unpleasant side-effects when they are force-fed facts or consume them accidentally. These may include nausea, vomiting, and severe gut pain. Extreme side effects of prolonged episodes of Factose Intolerance include a temporary inability to digest truthiness.
Factose itself is the main component of the meaty part of facts. In the normal population, it causes very little real harm, but true Heroes are allergic, much in the same way that some people have difficulty digesting milk products.
It is known that Bears are not Factose Intolerant in the least. However, Bears do have an intolerance to Truthiness, which is the secret weapon of true Heroes - they are so full of it that any Bear attempting to eat them will get quite sick or die.