Figure 1 Original impedance locus plots from the sigmoid colon of control (A) and mild to moderately inflamed Crohn's disease (B). Z_real gives the ohmic component and Z_imaginary the reactive component of the complex impedance. Intersections between the semicircle and the x axis at low and high frequencies represent total electrical wall resistance (R^t) and subepithelial electrical wall resistance (R^sub), respectively. R^t minus R^sub equals epithelial electrical wall resistance (R^e).