A randomized controlled trial was conducted to compare the clinical efficacy of Fu's subcutaneous acupuncture and western medication in the treatment of gastrointestinal dysfunction after knee surgery under general anesthesia. The difference in clinical efficacy between the Fu's subcutaneous acupuncture group and the western medication group was analyzed, and the mechanism of Fu's subcutaneous acupuncture in the treatment of gastrointestinal dysfunction after general anesthesia was further explored. It was confirmed that Fu's subcutaneous acupuncture can effectively promote postoperative gastrointestinal motility and reduce postoperative gastrointestinal discomfort. It can shorten the recovery time of gastrointestinal function, improve the quality of life of patients during the perioperative period, and explore the improvement of postoperative complications and promote the postoperative rehabilitation of patients, which is worthy of clinical application.

Postoperative gastrointestinal dysfunction refers to the symptoms such as abdominal distension, nausea and vomiting, constipation, and weakened or disappeared bowel sounds caused by preoperative anesthesia, postoperative fasting, use of analgesics, prolonged bed rest, and early drinking after surgery. It is a common complication of surgery. The use of opioid analgesics during and after general anesthesia can bind to the opioid receptors distributed in the presynaptic neurons of the intestinal muscle layer, resulting in the decrease of intestinal peristalsis waves and the cessation of motility, leading to the occurrence of postoperative gastrointestinal dysfunction, with an incidence of up to 81%. The delayed recovery of gastrointestinal function after surgery can lead to intestinal obstruction or paralysis, anastomotic leakage and other complications. It not only has adverse effects on the recovery process and quality of life, but also may increase the consumption of medical resources. Studies have shown that the incidence of Postoperative gastrointestinal dysfunction in abdominal surgery can be as high as 10% to 30%. In recent years, the incidence of Postoperative gastrointestinal dysfunction has not decreased significantly, but has increased by 10% in Japan. Patients with Postoperative gastrointestinal dysfunction have a longer hospital stay than those without POGD, and have more postoperative complications such as infection and postoperative intestinal obstruction, which brings a greater economic burden to patients and society. At present, a simple, convenient and effective method to restore gastrointestinal function is the key to reduce postoperative complications and rapid recovery to reduce the length of hospital stay, and it is also the key problem to be solved during the perioperative period.

Inclusion Criteria:

1. Met the diagnostic criteria for postoperative gastrointestinal dysfunction as defined in the Clinical Practice Guidelines for the Prevention and Treatment of Postoperative Gastrointestinal Dysfunction Using Integrated Traditional Chinese and Western Medicine;
2. Underwent elective knee surgery under general anesthesia;
3. Had normal bowel habits prior to hospital admission;
4. Were aged 18-80 years;
5. Had no severe systemic comorbidities or organic gastrointestinal disorders;
6. Provided written informed consent after receiving comprehensive information regarding the study's objectives, procedures, potential benefits, and associated risks.

All patients in both groups received standard postoperative symptomatic management, including routine wound dressing changes and patient-controlled analgesia.

Exclusion Criteria:

1. Patients with chronic diarrhea or constipation attributable to organic etiologies; those with confirmed organic lesions of the large intestine (e.g., inflammatory bowel disease, diverticulosis, or neoplasms); individuals diagnosed with malignant tumors; patients who developed postoperative complications including intra-abdominal infection, abdominal hemorrhage, or cerebrovascular events requiring transfer to the intensive care unit;
2. Patients with severe cardiac, hepatic, or renal dysfunction (e.g., NYHA Class IV heart failure, Child-Pugh Class C cirrhosis, or estimated glomerular filtration rate <30 mL/min/1.73 m²);
3. Patients with primary immunodeficiency disorders, active systemic infections, or uncontrolled autoimmune diseases;
4. Patients with recent abdominal trauma, acute surgical abdomen, or documented hypersensitivity to any intervention-related medications or materials;
5. Presence of active dermatological conditions-including macules, papules, erythema, urticaria, abrasions, lacerations, or ulcerations-at the intended site of Fu's subcutaneous needle insertion;
6. Patients exhibiting severe needle phobia, persistent vertigo, or cognitive/psychological impairment that precludes reliable adherence to treatment protocols or informed consent procedures;
7. Patients who initiated concomitant therapies (pharmacologic or non-pharmacologic) not stipulated in the study protocol after enrollment, thereby confounding efficacy assessment; and those with incomplete baseline or follow-up data essential for primary or secondary outcome evaluation.