  Comparison of heavy-ion experiments to fluid dynamics simulations requires
the conversion of the fluid to particles. Extending the approach in Molnar &
Wolff, PRC 95, 024903 (2017), this work presents self-consistent bulk viscous
corrections from kinetic theory for a one-component system with isotropic $2\to
2$ interactions. The phase space corrections are contrasted to the Grad ansatz
and also to corrections obtained from the relaxation time approximation. In
addition, the bulk viscosity of the system is calculated and compared with the
Grad result, as well as the $\zeta \propto (1 - 3 c_s^2)^2 \eta$ relation
between shear and bulk viscosity near the conformal limit. The possible
influence of various bulk correction choices on differential elliptic flow
$v_2(p_T)$ in heavy-ion collisions is also estimated.
