A trocar assembly for releasable engagement with an adapter assembly of a surgical stapling instrument includes a housing having a first end cap and a second end cap, a trocar member rotatably supported with the housing and movable between a retracted position and an advanced position, and a drive member rotatably supported within the housing. The trocar member includes a threaded body and defines a longitudinal channel. The drive member includes a drive portion received within the longitudinal channel of the trocar member. Rotation of the drive member causes longitudinal movement of the trocar member.
