Dynamic Changes and Influencing Factors of Acute Pain After Elastic Band Ligation of Internal Hemorrhoids in Patients With Mixed Hemorrhoids

AIM: To investigate the dynamic trajectory of acute pain after elastic band ligation of internal hemorrhoids in patients with mixed hemorrhoids and to analyze the independent factors influencing the pain trajectory.METHODS: This single-center retrospective study included 173 patients with mixed hemorrhoids (grade III or IV) who underwent elastic band ligation of internal hemorrhoids at the Department of Proctology, The People's Hospital of Tinghu District, between April 2022 and April 2025. Baseline data, preoperative Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), Social Support Rating Scale (SSRS) scores, and visual analog scale (VAS) pain scores on postoperative days 1, 3, 7, and 14 were collected. A growing mixture model (GMM) was used to identify pain progression trajectories. Univariate and multivariate logistic regression analyses were used to identify independent factors influencing trajectory categories, and receiver operating characteristic (ROC) curves were used to assess the discriminative power of risk factors.RESULTS: GMM analysis identified two pain progression trajectories: a rapid relief group (82 cases, 47.4%) and a poor relief group (91 cases, 52.6%). There were statistically significant differences in VAS scores at each postoperative time point and in intra-group time changes between the two groups (p < 0.001). Multivariate logistic regression analysis showed that age (odds ratio [OR] = 0.90, 95% confidence interval [CI]: 0.85–0.96, p = 0.002), SAS score (OR = 1.05, 95% CI: 1.01–1.10, p = 0.018), SDS score (OR = 1.05, 95% CI: 1.01–1.09, p = 0.009), SSRS total score (OR = 0.72, 95% CI: 0.65–0.81, p < 0.001), and number of ligations (OR = 4.96, 95% CI: 1.25–19.77, p = 0.023) were independent factors influencing the pain trajectory. ROC curve analysis showed that the area under the curve for the combination of these factors was 0.94 (95% CI: 0.91–0.97), the optimal cutoff value was 0.635, the sensitivity was 0.82, and the specificity was 0.96.CONCLUSIONS: Postoperative pain following elastic band ligation for mixed hemorrhoids exhibits heterogeneous trajectories. Younger age, higher preoperative anxiety and depression levels, lower levels of social support, and a greater number of ligations increase the risk of patients falling into an unfavorable relief trajectory. These factors may help identify patients at risk of unfavorable postoperative pain trajectories and inform individualized postoperative pain management.