An operable catheter between a folded guard and transport configuration and an expanded fluid drainage configuration from a body by means of a conduit that extends axially in a longitudinal direction from a proximal end to an opposite distal end, the catheter comprising: a proximal section (2), adapted to be completely inserted into a urinary canal of the body and constituting a proximal part of the duct, part extending axially between the proximal end and a first transition end of the proximal section, and - a distal section (1), adapted to be, at least partially, inserted into the urinary canal and constituting a distal part of the duct, part extending axially between a second transitional end of the distal section, and the distal end； the first transition end (204) being sized to allow its placement within a receiving portion of the distal part of the conduit to allow mutual displacement of the sections to operate the catheter between the folded configuration and the expanded configuration of the catheter, in that the sections comprise cooperating coupling structures to support the catheter in the expanded configuration； wherein the cooperating coupling structures comprise the fact that the internal surface of the distal section is formed with a groove (216) and because the external surface of the proximal section is formed with a key (217) that is interlockable with a slot (216), and that key (217) has the form of a flexible annular flange arranged in a transverse position with respect to the geometric axis of the catheter.Un catéter operable entre una configuración plegada de guarda y transporte y una configuración expandida de drenaje de fluido desde un cuerpo por medio de un conducto que se extiende axialmente en una dirección longitudinal desde un extremo proximal hasta un extremo distal opuesto, comprendiendo el catéter: - una sección proximal (2), adaptada para ser completamente insertada en un canal urinario del cuerpo y que constituye una parte proximal
