Understanding and Tailored Treatment of Low Anterior Resection Syndrome

Inclusion Criteria: General: * Must be able to read and understand Danish. * All participants must be adults and \>18 years and have full legal capacity. * Assessed by study personnel to have understood the research protocol, being able to comply with investigation procedures as well as ability to come to the hospital at the agreed timepoints, and to complete the trial. Specific inclusion criteria for LARS patients: * Patients operated for rectal cancer with a rectal resection and sphincter preserving surgery at a minimum of three months postop. * If patients have received a temporary protective ileostomy, this should have been reversed for a minimum of three months postop. Specific inclusion criteria for fecal incontinence patients and urge fecal incontinence patients * Patients planned for neuromodulation. * Satisfactory interoperative test results leading to permanent implantation of a pacemaker for sacral nerve modulation. Specific inclusion criteria for "watch and wait" patients: • Rectum/colon cancer patients treated with organ-preserving treatment, i.e., chemotherapy and radiotherapy with a complete clinical and radiological response at a minimum of 12 months posttreatment. Exclusion Criteria: General exclusion criteria * Persons that are not able to understand information * Connective tissue disorders * Parkinson's disease * Non-MRI compatible pacemaker, clips or other metal objects in the body. Patients implanted with a pacemaker for sacral nerve modulation will not undergo MRI postoperatively. * Piercings that cannot be removed before MRI * Claustrophobia * Allergic to latex * Abdominal diameter equal or more than 140 cm * Have other individual factors, in the opinion of the physician/healthcare professional, in which participating is contraindicated * Participation in concomitant clinical trial * Known intestinal obstruction, significant intestinal strictures or perforation. If in doubt about intestinal stricture, the patient will be examined with MRI of the small intestine, colonoscopy or other supplementing examination * Disorders of swallowing * Pregnant women Specific exclusion criterias for LARS patients * History of anastomotic leakage following rectal resection and sphincter preserving therapy * Evidens of local recurrence or dessimination of the cancer