  In this work, we study the implications of nonlinearity in general
relativistic spherically symmetric inviscid irrotational accretion flow in a
stationary non-rotating spacetime. It has been found that the perturbation
scheme leads to a differential equation of the form of general Li{\'e}nard's
equation. We discuss the equilibrium conditions of this system and its
implications for globally subsonic accretion flows in the spherically symmetric
stationary background. It is found that the stable solution predicted by linear
stability analysis may become unstable under inclusion of lowest order
nonlinearity.
