  The internal structure of a slowly rotating, charged black hole that is
undergoing mass inflation at its inner horizon is derived. The equations
governing the angular behavior decouple from the radial behavior, so all
conclusions regarding inflation in a spherical charged black hole carry through
unchanged for a slowly-rotating black hole. Quantities inflate only in the
radial direction, not in the angular direction. Exact self-similar solutions
are obtained. For sufficiently small accretion rates, the instantaneous angular
motion of the accretion flow has negligible effect on the angular spacetime
structure of the black hole, even if the instantaneous angular momentum of the
accretion flow is large and arbitrarily oriented.
