Development and Validation of a Risk Prediction Model for Postoperative Visceral Pain in Abdominal Surgery Patients

Inclusion Criteria: * Patients undergoing elective abdominal surgery under general anesthesia (including gynecological procedures and general surgery such as gastrointestinal, hepatobiliary, etc.); * Aged between 18 and 70 years; * Classified as American Society of Anesthesiologists (ASA) physical status II-III; * Expected surgery duration ≥ 2 hours. Exclusion Criteria: * History of previous abdominal surgery; * Diagnosed with chronic pain; * Long-term use of analgesics or other psychotropic medications; * Preoperative emergency condition; * Presence of severe comorbidities involving major organ systems; * Failure to complete postoperative pain follow-up.