A method for anastomosing an alimentary tract according to a first aspect of the invention includes a first step of inserting an endoscope into an alimentary tract through a natural opening in a state where a distal end part of a tube body is coupled to an outer periphery of a distal end part of the endoscope； a second step of making a hole in a tract wall of the alimentary tract； a third step of inserting the tube body through the hole； a fourth step of grasping the distal end part of the tube body disposed through the hole； a fifth step of separating the tube body from an outer periphery of the distal end part of the endoscope； and a sixth step of delivering the treatment part up to the hole after the fifth step.
