Correlations of anorectal pressure with the grading and prolapse of mixed hemorrhoids

Objective To analyze the relationships of anorectal pressure with the grading of mixed hemorrhoids and prolapse and explore the etiology of mixed hemorrhoid prolapse.

Methods A total of 200 patients with mixed hemorrhoids admitted to the Xi'an Hospital of Traditional Chinese Medicine from January 2021 to June 2025 were retrospectively selected. Anorectal resting pressure, anal canalsystolic pressure, rectal resting pressure, and rectal defecation pressure were measured to analyze their correlations with the grading and prolapse of mixed hemorrhoids.

Results Based on the degree of hemorrhoid prolapse and the ability to retract spontaneously (grade I was mainly characterized by hematochezia without prolapse; grade Ⅱ involved prolapse that could retract spontaneously; grade Ⅲ required manual retraction; grade Ⅳ exhibited persistent prolapse), 200 patients with mixed hemorrhoids were divided into Group A (grade Ⅰ), Group B (grade Ⅱ), Group C (grade Ⅲ), and Group D (grade Ⅳ), with 50 cases in each group. One-way analysis of variance for anal canal resting pressure showed that the anal canal resting pressures in Group A, Group B, Group C, and Group D were (48.90±12.09), (59.73±13.37), (65.86±13.59), and (80.24±18.35) mmHg, respectively, with statistically significant differences (F=40.412, P=0.001, η²=0.382, 95%CI, 0.272 to 0.464).For anal canal systolic pressure, rectal resting pressure, and rectal defecation pressure, which did not follow a normal distribution, the non-parametric Kruskal-Wallis H test was used. The results showed statistically significant differences in anal canal systolic pressure among the four groups (P=0.002, ε²=0.074), and in rectal defecation pressure among the four groups (P=0.005, ε²=0.064); no statistically significant differences were found in rectal resting pressure among the four groups (P=0.087, ε²=0.033). Spearman correlation analysis revealed that the grading of mixed hemorrhoids was significantly positively correlated with anal canal resting pressure (ρ=0.598, P < 0.001), anal canal systolic pressure (ρ=0.271, P < 0.001), and rectal defecation pressure (ρ=0.222, P=0.002). Logistic regression analysis indicatedthat anal canal resting pressure was an independent influencing factor for mixed hemorrhoid prolapse (P=0.001). The receiver operating characteristic curve showed that the area under the curve for anal canal resting pressure was 0.817 (95%CI, 0.759 to 0.876, P < 0.001). Using 66.5 mmHg as the diagnostic threshold, the sensitivity, specificity, and Youden's index were 0.560, 0.960, and 0.520, respectively.

Conclusion Anorectal pressure is closely related to the grading of mixed hemorrhoids, and anal canal resting pressure has significant predictive value for hemorrhoid prolapse.