Electroacupuncture (EA) Promotes Gastrointestinal Functional Recovery After Radical Colorectal Cancer Surgery

The goal of this clinical trial is to verify the efficacy of electroacupuncture in accelerating the recovery of gastrointestinal function after colorectal cancer surgery. The main questions it aims to answer are: * Whether electroacupuncture can accelerate the recovery of gastrointestinal function in patients after colorectal cancer surgery. * Whether electroacupuncture intervention is safe for postoperative colorectal cancer patients. Participants will be randomized into 3 groups: The conventional control group will receive postoperative rehydration and nutritional support, correction of acid-base imbalance and electrolyte disturbance, anti-infection, hemostasis and other symptomatic treatments. In the electroacupuncture group, acupuncture will be performed within 6 hours after surgery on the basis of the conventional control group. Acupoint: bilateral Hegu (LI4), Zhigou (SJ6), Zusanli (ST36), Shangjuxu (ST37). Both after obtaining Qi, and unilaterally connected to the electroacupuncture instrument for electrical stimulation, the current frequency is continuous wave 5 Hz, the intensity of stimulation was as the patient tolerated, each time lasting 30 min. Acupuncture stimulation was given every 12 h. The course of treatment was terminated postoperatively until the fourth postoperative day (d0-d4) or until the patient showed the first postoperative anal exhaust or continued until the fourth day. The sham acupuncture group will based on the conventional control group, using a blunt-tipped needle tip that do not pierce the adhesive pad.