  We consider a continuous atom laser propagating through a wave guide with a
constriction. Two different types of transmitted stationary flow coexist. The
first one coincides, at low incident current, with the non-interacting flow. As
the incident flux increases, the repulsive interactions decrease the
corresponding transmission coefficient. The second type only occurs for
sufficiently large incident currents and has a solitonic structure. Remarkably,
for any chemical potential there always exists a value of the incident flux at
which the solitonic flow is perfectly transmitted.
