  A generalized Van der Waals approach is developed for anisotropic fluids in
disordered porous media. As the reference system a hard spherocylinder fluid in
a disordered porous medium is considered and described in the framework of the
scaled particle theory with the Carnahan-Starling and Parsons-Lee corrections.
The attractive part of interaction is treated in the framework of the mean
field approximation in which due to orientational dependence of the excluded
volume of two spherocylinders, a coupling between attractive and repulsive
contributions is found. We focus on spherocylinder fluids with sufficiently
long particle lengths for which the nematic-nematic transition was established.
It is shown that these two nematic phases have different densities and are
characterized by different orientational ordering. Strong influence of the type
of interparticle attraction on the phase behaviour of anisotropic fluids in
disordered porous media is established. Three simple models for this purpose
are considered, namely a model with the Lennard-Jones anisotropic attraction, a
model with modified Lennard-Jones attraction and a model with anisotropic
square-well potential. For all considered models, the phase diagram shifts to
the region of lower densities and lower temperatures as the porosity decreases.
