Age

18–80

Sex

ALL

Healthy volunteers

Not accepted

18 years \< age \< 80 years
Tumor located in rectosigmoid (defined as 10- to 30-cm from the anal verge)
Pathological rectosigmoid carcinoma
Preoperative T stage ranging from T1 to T4a according to the 7th Edition of AJCC Cancer Staging Manual
Tumor size of 5 cm or less; 6) ECOG score is 0-1
ASA socre is Ⅰ-Ⅲ
Informed consent

Body mass index (BMI) \>30 kg/m2
Pregnant woman or lactating woman
Severe mental disease
Previous abdominal surgery
Emergency operation due to complication (bleeding, perforation or obstruction) caused by colorectal cancer
Requirement of simultaneous surgery for other disease

Safety Study of Transumbilical Single Incision Versus Conventional Laparoscopic Surgery for Colorectal Cancer