  We study atom-atom scattering in quasi-one-dimensional geometries with
transverse anisotropy. By assuming an s-wave pseudo-potential of contact
interaction, we show that the system would exhibit a single confinement-induced
resonance, where the scattering process degenerates to a total reflection as a
one-dimensional gas of impenetrable bosons. For a general form of interaction,
we present a formal calculation based on the two-channel model and conclude the
existence of only one confinement-induced resonance. Our findings are
inconsistent with a recent experiment by Haller et al. [Phys. Rev. Lett. 104,
153203 (2010)], where a splitting of confinement-induced resonances has been
observed in an anisotropic quasi-one-dimensional quantum gas of Cs atoms.
