Instrument for use in the treatment of prolapsed hemorrhoids

An instrument for use in the treatment of prolapsed hemorrhoids by applying a purse-string suture includes a tube, which has a distal end, with which it can be inserted forward into the rectum of a patient. The tube also has an open proximal end and a shell wall encompassing an inner hollow space and is provided with an elongated opening. The opening extends in the axial direction of the tube from a distal end to a proximal end. The instrument also includes a closure device, which in a closing position closes the opening and by which the opening can be successively exposed from the distal to the proximal end.