An anvil (300) for use in connection with a first member (10) of an anastomotic device (100) in the side wall of an intestine is provided. The anvil (300) comprises a distal head portion (301) and a connecting rod (302) extending proximally from the head portion (301). The distal head portion (301) has a first member retaining means (304), being displaceable laterally and centrally between a first member locking position and a first member releasing position. A tool (400) for use in connection with an anvil (300), according to above, is also provided, and a kit of parts comprising the two. The tool (400) comprises a receiving member (401) for receiving the connecting rod (302) of the anvil (300), and a seat (405) for a second member (20) of the anastomotic device (100), said seat (405) being arranged circumferentially of said receiving member (401), and said receiving member (401) being displaceable in relation to said seat (405).