Collisional transport of a high‐temperature plasma across the confining field of a bumpy torus magnetic confinement system depends sensitively upon the functional form of the radial guiding center drift, and thus upon details of the confinement geometry. A general and relatively explicit formula for the radial drift is derived, using the large aspect ratio results of a previous equilibrium study. Allowance is made for (i) arbitrary toroidal variation of the confining field; (ii) field distortion due to plasma currents; (iii) noncircular deformation of the toroidal field coils. However, the analysis pertains only to the plasma core, and not to the high‐beta annuli (electron rings) which are usually present in experiments. The question of bumpy torus omnigenity—whether any bumpy torus field configuration is consistent with a vanishing, or nearly vanishing, radial drift— is also investigated. It is found that omnigenity cannot occur, at least in the vicinity of the magnetic axis.