A surgical instrument for forming a gastrotomy. In various embodiments, the surgical instrument may comprise a hollow tip for attachment to a distal end of a tubular member such as an endoscope. In other embodiments, the hollow tip is integrally formed on the distal end of the endoscope. The hollow tip is configured such that when it is brought into contact with the inner layer of tissue in the stomach, the tissue is caused to stretch. A hole-forming device may be passed through the hollow tip to pierce through the stretched inner layer and adjacent outer layers of tissue to form a passageway therethrough for permitting surgical procedures to be performed therethrough. After the surgical procedures are performed through the passageway, the hollow tip is removed from contact with the inner layer of tissue to permit the inner layer of tissue to relax and to cause the holes formed through the inner layer and outer layers of tissue to be offset from each other.