Pain can be a conditioned response similar to conditioned nauseaassociated with chemotherapy. The behavior begins purely in response tothe presence of injury. It is then reinforced and becomes a conditionedresponse, an iatrogenic complication of treatment [12], particularly whenrewards are made contingent on the expression of pain behavior [21]. Theeffect of reinforcement is illustrated by the case of a 10-year-old girl who hadchronic daily abdominal pain for which no medical condition could befound. During episodes, her mother allowed her to rest in bed with her toysand watch television, and brought her food and drinks. After an hour or so,she would go back to play. After the mother stopped reinforcing thepatient’s pain behavior, the episodes rapidly diminished, as well as her use ofbelladonna and phenobarbital elixir [43].