Effectiveness of Sacral Neuromodulation in Low Anterior Resection Syndrome

"After the definitive implantation, stimulators are placed in position OFF for the first arm and in position ON for the second arm during 4 weeks.~Then all the stimulators are switched OFF (both first and second arms) for 2 weeks.~Finally stimulators are maintained in position ON for the first arm and switched OFF for the second arm during 4 weeks.~Since this is a cross-over study, patients can be randomly assigned to any arm first, but they will go to the other arm since the patient is its own control. 50% of randomized patients will go through ON-OFF and the other 50% OFF-ON.~After this cross-over phase, ALL stimulators will be in ON position until the end of the study period."