Postoperative ileus

Postoperative ileus is the pause in the gut’s movement after an operation, which stops food and gas passing and brings bloating, pain, nausea and vomiting. The 2025 colorectal guideline of the Enhanced Recovery After Surgery (ERAS) Society describes it as common after bowel surgery and usually self-limiting, and says a prolonged ileus lengthens the hospital stay, raises the risk of infection and slows recovery. Trials of acupuncture for it count hours: the time from the end of surgery to the first passing of gas (flatus) and the first bowel movement (defecation). Most use electroacupuncture, in which a small current runs between needles, given once a day for the first few days after surgery. Since 2013 most sham-controlled trials, the larger ones after laparoscopic (keyhole) cancer surgery, have reported first flatus or defecation brought forward by about 11 to 22 hours against sham, and the 2025 ERAS guideline lists acupuncture among the measures that may be used.

No Cochrane review

The Cochrane Library holds no review of acupuncture for postoperative ileus as of October 2026. It has reviewed chewing gum after surgery by Short and colleagues in 2015, which pooled 81 studies with 9,072 participants and found gum shortened the time to first flatus by 10.4 hours and to first bowel movement by 12.7 hours; it is a reference point for the size of the effects below, not a review of acupuncture.

Later reviews

Five systematic reviews cover the trials. They differ in which operations and which controls they admit, so the table keeps them apart. Sham acupuncture here means shallow needles at points away from the classical ones, or electrodes with no current; usual care means the hospital’s standard recovery programme without any needling.

Yuan’s review used trial sequential analysis, which asks whether the pooled trials hold enough people to trust a result; it found enough for time to defecation and flatus and too few to say whether electroacupuncture prevents a prolonged ileus. Liu’s review found the strongest evidence for electroacupuncture at ST36 (Zusanli), and it is the review the ERAS guideline cites.

Landmark trials

• Usual care, 2010. A trial at Fudan University Cancer Hospital in Shanghai by Meng and colleagues randomised 90 people after abdominal surgery for colon cancer to daily electroacupuncture for up to 6 days or usual care. It found no difference in prolonged ileus, defined as no flatus or bowel movement by 96 hours, or in quality of life.
• Sham and no treatment, 2013. A trial in Hong Kong by Ng and colleagues randomised 165 people having laparoscopic surgery for colon or upper rectal cancer to electroacupuncture, sham acupuncture or no acupuncture, once a day on days 1 to 4, at ST36, SP06 (Sanyinjiao), LI04 (Hegu) and TB06 (Zhigou). Time to defecation averaged 85.9 hours with electroacupuncture, 107.5 with sham and 122.1 with none, and the electroacupuncture group also needed less pain relief.
• Sham, 2013. A trial at Memorial Sloan Kettering Cancer Center in New York by Deng and colleagues gave 90 people after colectomy for colon cancer true or sham acupuncture twice a day for 3 days. Recovery, measured as the later of tolerating solid food and first flatus or bowel movement, took 149 hours with acupuncture and 146 with sham. The authors note the spread of results was far wider than planned for, so a larger trial might be needed.
• Stimulation through the skin, 2021. A trial in 10 Chinese hospitals by Gao and colleagues gave 610 people having colorectal surgery transcutaneous electrical acupoint stimulation, a current through skin pads with no needles, at ST36, ST37 (Shangjuxu) and SP06, or the same pads with no current. Ileus, defined as no flatus for more than 72 hours, affected 32.3% against 41.0%.
• One point against another, 2022. A single-centre trial in Beijing by Yang and colleagues randomised 105 people after laparoscopic colorectal cancer surgery to electroacupuncture at ST36, electroacupuncture at ST25 (Tianshu), or standard care alone. ST36 shortened the time to flatus and to defecation against standard care; ST25 did not.
• Sham, within an ERAS programme, 2023. A multicentre trial in China by Wang and colleagues, published in JAMA Surgery, randomised 249 people having laparoscopic colorectal cancer surgery under an ERAS protocol to four daily sessions of electroacupuncture at CV12 (Zhongwan), ST25, ST36 and ST37, or sham needling at non-acupoints with the current cut. Median time to first defecation was 76.4 hours against 90.0, and prolonged ileus affected 10% against 20% (risk ratio 0.51). Hospital stay and readmission did not differ, and no serious adverse event occurred. The authors list as limitations that patients’ expectations differed between groups, that the trial ran in a culture that expects acupuncture to work, and that compliance with the ERAS protocol was not measured.
• Sham and standard care, gastric surgery, 2025. A trial in 7 Chinese hospitals by Pei and colleagues, published in Gastroenterology, randomised 585 people having laparoscopic gastrectomy for stomach cancer to four sessions of electroacupuncture, sham electroacupuncture or standard care. Electroacupuncture brought first flatus 13.0 hours sooner than sham and 24.5 hours sooner than standard care, and lowered the rate of prolonged ileus against both. No severe adverse event was reported.

What guidelines say

The ERAS Society’s guideline for elective colorectal surgery, by Gustafsson and colleagues, was published in Surgery in June 2025, follows the 2018 edition and is the newest colorectal guideline on the Society’s list in October 2026. Its recommendation on ileus is a multimodal approach, graded strong, and its table of individual measures rates acupuncture as effective at shortening the time to flatus and first defecation, on low-quality evidence, with the recommendation “may be used (weak)”. It gives the same rating to acupuncture combined with simo decoction, a herbal drink. Transcutaneous electrical acupoint stimulation, on the strength of the Gao trial, is rated moderate quality with “can be used (moderate)”, the same grade as chewing gum. For acupuncture the guideline cites the 2018 Liu review; it does not cite the 2023 Wang trial or the 2025 Pei trial.

What the reviews could not settle

Nearly every trial in these reviews ran in China. Meng’s trial in Shanghai and Deng’s in New York found no benefit, and both were small. The Wang trial’s authors ask for their result to be extended to other countries with caution. Yuan’s analysis found the trials too few to show whether electroacupuncture prevents a prolonged ileus, and Zhu’s review found electroacupuncture did not shorten the hospital stay against sham. The large trials are of laparoscopic surgery for bowel and stomach cancer, so they say nothing directly about open surgery or operations for other conditions, and Zhu’s review found adverse events reported too seldom to judge safety in full. Yang’s trial found ST25 made no difference where ST36 did, and which points matter has not been tested at scale.

Sham acupuncture explains what a sham control can and cannot rule out. Nausea after surgery and postoperative pain report the trials in two other problems of recovery, and constipation those in chronic slow bowels. AcuiQ’s postoperative ileus and postoperative gastrointestinal dysfunction pages list the protocols individual studies prescribed, each with its citation.