A surgical stapling instrument includes an elongate body portion defining a longitudinal axis, and an end effector supported on a distal portion of the elongated body portion. The end effector includes a housing having a base portion and a jaw portion, an anvil assembly supported on the jaw portion, and a cartridge assembly releasably supported on the base portion. A tissue guide member is operably secured relative to the cartridge assembly to facilitate alignment of the cartridge assembly through a firing stroke.