An interaction region (IR) with head-on collisions is considered as an
alternative to the baseline configuration of the International Linear Collider
(ILC) which includes two IRs with finite crossing-angles (2 and 20 mrad).
Although more challenging for the beam extraction, the head-on scheme is
favoured by the experiments because it allows a more convenient detector
configuration, particularly in the forward region. The optics of the head-on
extraction is revisited by separating the e+ and e- beams horizontally, first
by electrostatic separators operated at their LEP nominal field and then using
a defocusing quadrupole of the final focus beam line. In this way the septum
magnet is protected from the beamstrahlung power. Newly optimized final focus
and extraction optics are presented, including a first look at post-collision
diagnostics. The influence of parasitic collisions is shown to lead to a region
of stable collision parameters. Disrupted beam and beamstrahlung photon losses
are calculated along the extraction elements