A trocar for positioning within a body lumen such as an intestine is disclosed. The trocar has a window adjacent its distal end in communication with the internal lumen of the trocar. The trocar is sufficient rigid to stabilize the body lumen upon positioning therein to maintain patency of the body lumen. A slot in communication with the window extends to the distal end of the trocar.A surgical procedure for reversing a colostomy procedure is also disclosed. The above described trocar is inserted into a first intestinal section through an opening in the abdominal wall. A guide wire is introduced through the rectal opening and advanced through the rectal stump and out the opening in the abdominal wall. An anvil is connected to the guide wire and the guide wire withdrawn through the rectal opening to advance the anvil within the first intestinal section. An anastomosis instrument is introduced through the rectal opening and connected to the anastomosis instrument. The anastomosis instrument is fired to connect the two intestinal sections to reestablish continuity between them.
