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.

Colorectal cancer is the most common and predominant malignancy, and radical resection surgery, as the main method of current treatment for colon and gastrointestinal cancers, is performed on a large number of patients each year. Clinically, abdominal surgery causes the highest frequency of gastrointestinal dysfunction and the longest relative duration of dysfunction. A condition in which gastrointestinal function has not fully recovered after abdominal surgery is called gastrointestinal dysfunction. The common symptoms of postoperative gastrointestinal dysmotility are abdominal distension, abdominal pain, nausea and vomiting, diminished or even absent bowel sounds, loss of anal discharge, loss of bowel movements, and even secondary symptoms such as fever and pulmonary infection. It will adversely affect patients' postoperative quality of life to varying degrees, weaken their gastrointestinal barrier capacity, and severe gastrointestinal dysfunction can lead to complications such as electrolyte disorders, intestinal adhesions, intestinal obstruction, anastomotic fistula, and abdominal wall incision dehiscence in patients, as well as increase the social burden and the economic burden of patients. Some clinical reports show that acupuncture has good efficacy on gastrointestinal dysfunction, and acupuncture has effects on the gastrointestinal tract such as promoting gastrointestinal motility and reducing the inflammatory response of the gastrointestinal tract. In this study, a multicenter, randomized, blinded, sham acupuncture-controlled clinical design will be used to verify the efficacy of postoperative electroacupuncture in accelerating the recovery of gastrointestinal function after colorectal cancer surgery.

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. In other words, the electroacupuncture instrument show the state of being connected, but it is not actually energized; the acupuncture points, acupuncture time points, frequency, retention time and treatment duration were the same as those of the intervention group.

Inclusion Criteria:

1. Surgical patients who meet the diagnostic criteria for colorectal cancer and require elective radical colorectal cancer surgery;
2. 18 years old ≤ age ≤ 79 years old, with no restriction on gender;
3. Understand, agree to participate in this study and sign the informed consent form;
4. American society of Aneshesiologists (ASA) classification I to III.

Exclusion Criteria:

1. Patients with psychiatric disorders;
2. Patients who have participated or are participating in other clinical studies in the 3 months prior to enrollment;
3. Patients with severe malnutrition (NRS2002 score ≥ 3);
4. Patients with total colectomy;
5. Patients undergoing ileal diversion for rectal cancer;
6. Patients with tumor infiltration requiring resection of other organs;
7. Prophylactic fistulae.

Anyone who meets any of the above criteria will be excluded from the study.

All individual participant data that underlie results in a publication.

Starting 12 months after publication.

For academic communication only, online supplementary documents and email communication can be added.

Both groups will use adhesive pads, and the sham acupuncture needle will have the same appearance as the traditional needle, with a blunt tip (Suzhou Medical Supplies Factory, specification 0.25×40mm), lifting and inserting and twisting, but not piercing the adhesive pad. The output wire of the special sham electroacupuncture apparatus is cut in the middle, and the appearance is as usual; that is, the electroacupuncture apparatus shows an on state, but is not actually energized; the electroacupuncture points, acupuncture time points, frequency, retention time, and duration of treatment are the same as the intervention group.

All study patients will be treated independently and separately, ensuring that patients will not come into contact with each other. To test the effectiveness of blinding of participants, two hospitals will be selected from for blinded success assessment.