A catheter includes an elongated tubular body including a first wall andsecond walldefining first and second lumens, respectively. Each wall extends to a distalend and defines adistal opening. The first and second walls may each include one or more sideopeningsdisposed proximal of the distal end. The first and second lumens are separatedby a septum.The septum includes a septum extension extending distally from the septum. Theseptumextension is adapted to articulate relative to the septum in response to fluidflow into and out ofthe distal openings of the first and second lumens. The septum extension isdimensioned topartially obstruct fluid flow into the catheter through one of the distalopenings upon thearticulation of the septum extension.
