Early mobilization is considered as an important strategy to enhance postoperative recovery. However, direct association between very early mobilization and improved recovery needs randomized control trials to prove. This study proposes the program of walking out from operating room (WOFOR) after surgery, which means that encouraging patients to walk out from the operating room and return to the ward by walking under the condition of painlessness, clear consciousness and normal muscle strength of lower limb. The aim of this randomized controlled trial is to investigate the effect of WOFOR on the postoperative recovery of patients undergoing laparoscopic colorectal surgery.

Postoperative bed rest increases the risk of complications such as thromboembolism and intestinal adhesion. Encouraging early mobilization after surgery should be important, although actual effects of early mobilization still need randomized control trails to prove. The aim of this randomized controlled trial is to investigate the effect of walking out from operating room (very early mobilization after surgery) on the postoperative recovery of patients undergoing laparoscopic colorectal surgery.

A sample size of 300 patients in each group will be selected by a prior power analysis on the basis of the following assumptions: (1) an absolute reduction in the length of the hospital stay by 1 day ( 9 days in intervention group and 8 days in control group), (2) standard deviation 3 days, (3) α=0.05, (4) power 80% and .(5) missed follow-up rate 5%.

Patients will receive written and verbal information about the trial before written consent is obtained. The randomization will take place before the day of the surgery and the patients will be assigned to either intervention (return to ward by walking) or control group (return to ward by lying on the transporting bed ). A stratified randomization with three factors including sex(female or male), tumor site (colon or rectum) and age (18-40 or 41-65 years old ) will be performed to ensure an even spread. The randomization is performed using concealed allocation where envelopes are prepared externally using a randomization list prepared by a statistician.

The patients will receive general anesthesia combined with epidural analgesia. After surgery, the patients will be evaluated whether fulfilling the criteria for mobilization including stable physiological parameters, consciousness, normal level of orientation and muscle strength, and painlessness every ten minutes. If patients fulfill the criteria, they will receive different methods of returning to the ward based on the grouping. In the control group, the patient will return to the ward by lying on the transporting bed. In the intervention group, the patients will be raised to a sitting position for five minutes. If the patients do not complain any discomfort and have stable physiological parameters, they will be encouraged to stand. If standing do not cause any discomfort, they will be encouraged to walk within the range of 5-meter long and 60-centimeter wide. If patients can walk within the range, they will return to the surgical ward by walking under the protection of medical staffs.

Then, all study patients will be subject to the same management such as the guidance of drink and diet recovery, the guidance of mobilization in the ward (the duration and distance of walking in the ward will be recorded every day), nutrition supplement after surgery, and the criteria of drainage removal and hospital discharge. The outcomes such as the length of hospital stay after surgery will be recorded and analyzed to evaluate the effects of walking out from the operating room. The analysis of Intention-to-treat and Per-protocol-sets will be both performed by statisticians.

Summary statistics of mean (SD) for normally distributed data or median (IQR) for skewed data will be generated for continuous variables, and frequency (percentage) will be generated for categorical or ordinal variables. Continuous variables will be analyzed by Student's t test or Mann-Whitney U test or Repeated Measures Analysis of Variance, and categorical outcomes will be analyzed by χ² test.

Inclusion Criteria:

• 1. Age 18-65 Years old
• 2. scheduled for laparoscopic colectomy or laparoscopic rectectomy surgery (Dixon technique)
• 3. American Society of anesthesiology (ASA) grade I or grade II

Exclusion Criteria:

• 1. Patients have severe cardiac diseases (cardiac function grading greater than grade 3/arrhythmia including sick sinus syndrome, atrial fibrillation, atrial flutter, atrioventricular block, frequent ventricular premature, multiple ventricular premature, ventricular premature R on T, ventricular fibrillation and ventricular flutter/acute coronary syndrome) or respiratory failure or hepatic failure or renal failure;
• 2. Patients with poor blood glucose control (glycosylated hemoglobin>7%);
• 3. Patients with poor blood pressure control (receive regular antihypertensive medical treatment but still have systolic blood pressure > 150 mmHg and/or diastolic blood pressure > 90 mmHg );
• 4. Patients have schizophrenia, epilepsy, Parkinson's disease, mental retardation, or hearing impairment.
• 5. Patients have thrombosis such as in lower extremity or in other veins.
• 6. Patients have neuromuscular disorders affecting lower limb activity, such as myasthenia gravis and cerebral infarction, which cause lower limb muscle weakness;
• 7. Patients have contraindications for epidural puncture.
• 8. Patients refuse to sign informed consent for research.