A catheter that is operative between a folded configuration for storage and transport and an expanded configuration for draining fluid from a body through 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 inserted completely into a urinary canal of the body and forming a proximal part of the duct whose part extends axially between the proximal end and a first transition end (5) of the proximal section , and - a distal section (1), adapted to be at least partially inserted in the urinary canal and forming a distal part of the duct whose part extends axially between a second transition end (3) of the distal section and the end distal, the first transition end (5) being sized to allow its positioning within a receiving part of the distal part d the conduit to allow axial movement of the sections relatively with each other to operate the catheter between the folded configuration and the expanded configuration of the catheter, in which the sections (1, 2) comprise cooperating coupling structures to support the catheter in the expanded configuration , and the proximal section (2) forms a first outer surface with a circumference that increases from a proximal end to the first transition end (5), characterized in that the distal section (1) forms a second outer surface with a circumference that decreases from the distal end to the second transition end (3).Un catéter que es operativo entre una configuración plegada para almacenamiento y transporte y una configuración expandida para drenar fluido de un cuerpo a través de un conducto que se extiende axialmente en una dirección longitudinal desde un extremo proximal a un extremo distal opuesto, comprendiendo el catéter: - una sección proximal (2), adaptada para ser insertada completamente en un canal urinario del cuerpo y que forma una parte proximal del conducto cuya parte se extiende axialmente entre el ex
