The ∇B drift in the toroidal magnetic field leads to relatively large radial displacements as the parallel velocity of an ion passes through zero. If collisional scattering into this velocity band is unable to balance the enhanced radial diffusion, a minimum will develop in the velocity distribution. This happens when ρθ/rn > (rνi/vΘ)½, where = r/R is the inverse aspect ratio of the torus, Θ = Bθ/Bφ is the ratio of poloidal and toroidal components of the magnetic field, v = (2T/M)½ is the ion thermal speed, ρθ = Mv/eBθ is the ion Larmor radius in the poloidal magnetic field, rn is the density scale length, and νi is the ion-ion collision frequency. As ρθ/rn increases, the minimum deepens, and beyond (rν/vΘ)1/3 the distribution has a loss-band character. The analysis is restricted to the "plateau" collisional regime. The velocity distribution is derived by solving the collisional kinetic equation, including the radial loss and an isotropic source term. The radial loss term is dominant only over a limited velocity band, the resonant band. Solutions valid within the resonant and non-resonant velocity ranges are matched at the transition between these ranges.For typical Tokamak parameters, the predicted anisotropy in the ion velocity distribution is very weak, being of order 1%. However, it should be quite strong in existing stellarators. Observations in the Proto-Cleo stellarator are not inconsistent with theoretical predictions.