Patient: Description of condition (onset, main symptoms, hospital visited, etc.): January 2011 onset, diarrhea, blood in stool, prolapse. Department of Anorectal Medicine, Guiyang Medical College, Guizhou Province. Large mass, had a course of radiotherapy 25 times and 4 times of chemotherapy. Can I receive anal preservation surgery at your hospital. Zhang Shurong, Oncology Center, Beijing Tongren Hospital: Usually, anal preservation is not recommended for tumors less than 6 cm from the anus. Of course, whether anal preservation is possible depends not only on the location of the tumor, but also on the size of the tumor, the depth of invasion, the width of the pelvic cavity, the degree of differentiation of the tumor and the experience of the physician. The fundamental question of whether to preserve anus or not is the completeness of tumor removal and safety of surgery as well as the return of anal function after surgery. If you receive high dose radiotherapy before surgery, preserving the anus will increase the risk of anastomotic fistula and the tumor is large; therefore, we do not recommend you to undergo the surgery of preserving the anus.