Rectal Disorders

The treatment of rectal cancer is currently based on surgical resection of the rectum with total excision of the mesorectum, associated with neoadjuvant radiochemotherapy. Surgical resections with sphincter preservation are frequently (60% of cases) associated with problems related to intestinal and defecatory function, which together are called Anterior Resection Syndrome (ARS) with varying degrees of severity. Among the different treatments the investigators find posterior tibial nerve stimulation, a simple and non-invasive technique, which is currently used. The study aims to analyze whether postoperative posterior tibial nerve stimulation in patients undergoing low anterior resection of the rectum has an impact on the incidence and duration of low anterior resection syndrome (LARS) and therefore on the quality of life of patients undergoing this type of intervention. Therefore, treatment with PNTS is currently established for the management of LARS symptoms. Given that a large percentage of patients operated on for rectal neoplasms will develop this syndrome, the investigators intend to apply this treatment before the onset of symptoms in patients at risk for LARS. It is also an intervention with a low rate of side effects, the benefit that the investigators can obtain from its preventive application is clearly superior to the risk of undergoing such treatment. The investigators´ hypothesis is: Posterior tibial stimulation for 6 weeks post-operative of low anterior resection with anastomosis has a favorable impact by reducing the incidence and duration of ARS and improving the quality of life of patients undergoing anterior rectal resections for cancer.