Low anterior resection syndrome

Low anterior resection syndrome is a complication that follows low anterior resection, a surgical procedure used to remove the rectum, most commonly performed to treat rectal cancer. Rather than arising from the cancer itself, the syndrome is a consequence of the surgery: risk is shaped by factors including where the original tumor was located and whether the patient received radiation therapy either before or after the operation. The syndrome manifests in two broad, sometimes overlapping symptom patterns. One cluster centers on urgency, incontinence, and increased frequency of bowel movements, while the other centers on constipation, a sensation of incomplete evacuation, and difficulty fully emptying the bowel; some patients describe features of both patterns, either alternating between them or experiencing both at once. Additional reported symptoms include changes in stool frequency or consistency, generally unpredictable bowel function from day to day, and painful defecation, all of which can significantly affect quality of life after otherwise successful cancer surgery and often require ongoing management by the treating surgical or gastroenterology team.