Operators and teams. Procedures were performed by multiple attending colorectal surgeons working on routine service teams. All surgeons were credentialed for laparoscopic colectomy and adhered to a standardized operative approach with harmonized anesthesia protocols and perioperative order sets across teams.

Group allocation. Patients were not randomized. During the study period at The First Affiliated Hospital of Yangtze University, consecutive eligible patients were managed according to the perioperative pathway routinely used by the admitting surgical team. Teams that had fully implemented ERAS delivered the ERAS pathway, whereas teams that maintained conventional practice delivered standard care. Patients were informed of the relevant pathway on admission and consented to follow it. No allocation concealment was applied.

This single-center controlled study enrolled 100 consecutive patients who underwent laparoscopic radical colectomy at a tertiary hospital between September 2023 and October 2024. Patients were managed either by an ERAS pathway (n = 53) or conventional perioperative care (n = 47). Baseline characteristics were comparable between groups, including sex distribution (male/female 27/26 vs 23/24), age ((66.66 ± 5.65) years vs (67.70 ± 6.52) years), and body mass index ((24.04 ± 2.58) kg/m² vs (24.18 ± 2.59) kg/m²).

As summarized in Table S1 , age, sex, and BMI did not differ significantly between groups; additional baseline variables are provided to facilitate assessment of potential confounding.

Inclusion criteria were: age < 80 years; histologically confirmed colon cancer; no distant metastasis on imaging (TNM stage ≤ III); planned laparoscopic radical colectomy; and complete clinical data. Exclusion criteria included: emergency surgery or preoperative intestinal obstruction; severe organ dysfunction, severe anemia, or marked malnutrition; prior abdominal surgery or neoadjuvant chemoradiation; preadmission nasogastric tube placement or prolonged fasting requiring nutritional support; conversion to open surgery, postoperative ICU admission, or inability to comply with pathway management.

The ERAS pathway comprised: preoperative counseling with expectation management and shortened fasting, avoidance of routine mechanical bowel preparation; intraoperative temperature and fluid optimization with short-acting anesthetics and opioid-sparing techniques [8] , and avoidance of routine nasogastric and abdominal drains; postoperative early oral feeding (progressing from clear fluids to semi-liquid diet). Early ambulation, adequate analgesia and antiemetic prophylaxis, and early removal of urinary catheters and drains [9] . Conventional care followed traditional practices with longer fasting, more conservative postoperative feeding strategies, greater reliance on tubes and drains, and restricted ambulation.

Primary outcomes were postoperative LOS (days) and total hospital cost (10,000 RMB). Secondary outcomes were recovery milestones: time to first semi-liquid diet, first flatus, first bowel movement, and first ambulation (days).

Clinical and cost data were retrieved from the electronic medical record and hospital information systems and verified independently by two researchers. An ERAS team (surgeons, anesthesiologists, nurses, and dietitians) standardized patient education materials, daily diet and activity schedules, and pain assessment forms. Cases with missing key variables were excluded before the database lock.

Baseline socio-demographic and clinical variables (age, sex, BMI, ASA class, tumor site/stage, common comorbidities) are summarized in Table S1 . Continuous variables are reported as mean ± SD and categorical variables as n (%); between-group comparisons used the t-test or χ²/Fisher’s exact test as appropriate.

Analysis population. We conducted a per-protocol analysis. Patients who required intraoperative conversion to open surgery were excluded a priori because conversion substantially alters postoperative recovery and deviates from the intended laparoscopic ERAS pathway. Primary outcomes were compared between groups using the same tests described above.

Continuous variables were expressed as mean ± standard deviation or median (interquartile range), and categorical variables as counts (%). Between-group comparisons used the independent-samples t-test or the Wilcoxon rank-sum test as appropriate. We report mean differences with 95% confidence intervals and Hedges’ g standardized effect sizes to facilitate cross-study comparison.

There were no statistically significant differences between groups in age, sex, or BMI, indicating baseline comparability. All patients underwent laparoscopic radical colectomy; no major sources of bias were identified at baseline. See Table S1 .

LOS was significantly shorter in the ERAS group than in conventional care ((7.94 ± 1.73) days vs (10.72 ± 2.72) days; mean difference −2.78 days, 95% CI −3.70 to −1.86; Hedges g ≈ −1.23), representing an approximate 25.9% relative reduction. Total cost was also lower with ERAS ((5.16 ± 0.69) × 10,000 (RMB) vs (5.57 ± 0.99) × 10,000 (RMB); mean difference −0.41 × 10,000 (RMB), 95% CI −0.75 to −0.07; Hedges g ≈ −0.48), corresponding to a relative decrease of about 7.4%. ( Table 1 )

These improvements likely reflect synergistic effects of early feeding and ambulation, opioid-sparing analgesia, and goal-directed fluid therapy. ( Table 2 )

The combination of faster functional recovery with shorter LOS and lower cost suggests a coherent pathway effect: “faster recovery → shorter LOS → lower cost.”

Note: Data are mean ± standard deviation; t denotes the independent‑samples t‑test statistic.

Note: Data are median (interquartile range); Z denotes the Wilcoxon rank‑sum test statistic.