A surgical method for placing an implantable medical device for constricting at least one of a patient's rectum, anal channel, anal sphincter or colon. The surgical method comprises creating an incision in a vaginal wall of a patient, inserting a surgical instrument through said incision. The instrument comprising an elongated main part, an elongated member having a proximal end fixed to a distal end of the elongated main part by means of a first adjustable joint having a pivotal axis, for adjusting a first angle between the main part of the instrument and the elongated member between 0 and 180 degrees, wherein the elongated main part and the elongated member lie in a first plane extending perpendicularly to the pivotal axis. The surgical method further comprises a flexible tip attached to a distal end of the elongated member and exhibiting a conformation which is reversibly changeable from an essentially straight conformation to a loop or hook conformation, wherein the flexible tip, when in the loop or hook conformation, defines an opening with an axial hole going there through, and wherein a second plane extends perpendicularly to the axial hole through said loop or hook, so that the flexible tip, in its loop or hook conformation, lies in the second plane. The surgical method further comprises using said flexible tip for placing the implantable medical device encircling the patient's rectum, anal channel, anal sphincter or colon.