Abstract: The drain of this invention includes a tube provided with orifices for drawing in residual secretions gathered at the site of an operation. Within the tube is bounded a volume of variable capacity. Such volume is divided into one or several inflatable pockets bounded between the internal wall of the tube and a sleeve judiciously fastened to said wall. Such sleeve is of elastic material. A suction source is connected to the channel left free within the tube by the sleeve. Furthermore, a fluid source may be connected to the volume bounded by the sleeve to enable changing the capacity thereof. Such changes serve to unclog the intake orifices.The invention is applicable to surgical drains used in the post-operational phase to remove all secretions appearing at the site of the operation.