A surgical instrument including a handle assembly, an elongated portion, anend effector,and a stop member is disclosed. The end effector is disposed adjacent a distalportion of theelongated portion and includes a first jaw member and a second jaw member. Atleast one jawmember is movable with respect to the other jaw member between spaced andapproximatedpositions. The first jaw member includes an upper tissue-contacting surfaceand a lower shelfportion. The shelf portion includes a groove disposed therein. The stop memberis disposedadjacent a distal portion of the first jaw member and is pivotable withrespect to the first jawmember between a first position, a significant portion of the stop memberbeing positionedexternal to the first jaw member, and a second position where a lower portionof the stop memberbeing positioned at least partially within the groove.
