Importance of some technical aspects of the procedure of percutaneous posterior tibial nerve stimulation in patients with fecal incontinence Rodolfo Rodríguez Carrillo; María Dolores Ruiz Carmona; Rafael Alós Company; Andrés Frangi Caregnato; Marina Alarcón Iranzo; Amparo Solana Bueno; Roberto Lozoya Trujillo; Eduardo García-Granero Ximénez;