  We study the propagation of the quantum field perturbations in the interior
of the Schwarzschild black hole. The interior of the black hole is like an
anisotropic cosmological background which expands in one extended direction
while contracting in azimuthal directions. Solving the quantum mode functions
approximately, we calculate the expectation values of physical quantities such
as the energy density $\langle \rho \rangle$ and pressure $\langle P\rangle$ as
measured by an observer in the interior of the black hole. We employ a
combination of the $\zeta$ function regularization and dimensional
regularization schemes to regularize the UV divergences in the energy momentum
tensor associated to these quantum perturbations. By solving the Einstein field
equations, we calculate the quantum backreactions induced in the background
geometry. We speculate that the effects of quantum fluctuations in the interior
of the black hole can be measured by the exterior observer.
