  We revisit the important issue of charge fluctuations in the two-dimensional
$t{-}J$ model by using an improved variational method based on a wave function
that contains both the antiferromagnetic and the d-wave superconducting order
parameters. In particular, we generalize the wave function introduced some time
ago by J.P. Bouchaud, A. Georges, and C. Lhuillier [J. de Physique {\bf 49},
553 (1988)] by considering also a {\it long-range} spin-spin Jastrow factor, in
order to correctly reproduce the small-$q$ behavior of the spin fluctuations.
We mainly focus our attention on the physically relevant region $J/t \sim 0.4$
and find that, contrary to previous variational ansatz, this state is stable
against phase separation for small hole doping. Moreover, by performing
projection Monte Carlo methods based on the so-called fixed-node approach, we
obtain a clear evidence that the $t{-}J$ model does not phase separate for $J/t
\lesssim 0.7$ and that the compressibility remains finite close to the
antiferromagnetic insulating state.
