Food intolerance testing as devised by Dr. Carroll is similar in some respects to the bioelectronic testing of Voll, from which many biofeedback mechanisms currently in use have evolved. In the testing, a blood sample is placed in a specific electric circuit, and exposed to various foods in contact with a reagent. Fluctuations in the current are detected, and thereby the outcome of the testing determined. The lecture will focus on the history of the method, its clinical use, and differentiating food intolerance testing versus allergy testing.