We have developed a novel modal solver that supports transverse anisotropic materials. The modal solver consists of the Interior Penalty Discontinuous Galerkin Method combined with a standard Finite Element Method to solve the full-wave Maxwell's curl-curl equation. Here we have used the method to analyze an anisotropic plasmonic metal-insulator-metal (MIM) waveguide. The waveguide comprises a gold-BaTiO3-gold layer that allows for a strong electro-optic effect. A simplified multi-physics approach was used to take into account the large Pockels effect in the BaTiO3 layer.