A surgical instrument comprising an elongate body which ends with a tool carrier and which is intended to be introduced into the peritoneal cavity by way of a trocar, the body comprising:an internal tube, which extends along a longitudinal axis of the body and which ends with a bendable standan external tube, which extends around the internal tube, coaxially with respect to the internal tube, and which is mounted so as to rotate about the internal tube the external tube ending with a bellows, which extends around the stand and which, at its end, bears the tool carrier.
