Postoperative Bowel Function After SPS by Different Reconstruction Methods

Colorectal cancer is one of the most common malignant tumors in the world. Surgery is still the main treatment for rectal cancer. With the popularization of stapler technology and the application of preoperative neoadjuvant therapy, more and more patients with rectal cancer have treated sphincter preservation surgery for rectal cancer. postoperative observation found that some patients with rectal cancer anus-preserving surgery had different degrees of defecation dysfunction after surgery, such as incontinence, tightness, increased frequency of bowel movements, and constipation. These clinical symptoms have been classified as "Low anterior resection syndrome (LARS)" in recent years.Now there is no treatment for LARS.Meanwhile,J-pouch and side-to-end anastomosis can help the patients,but there is few trials can prove this.This trial means to prove weather side-to-end anastomosis can improve bowel of rectal patients afer surgery.