Sensory threshold for defecation and its correlation with pelvic organ prolapse: An exploration of related factors

Abstract

Objectives: This research aimed to investigate changes in defecation sensory threshold and related factors in patients with posterior vaginal wall prolapse. Methods: A total of 214 patients with pelvic organ prolapse were recruited between October 2019 to January 2021. All patients underwent a defecation sensory threshold examination, physical examination, and pelvic floor ultrasound examination. Factors related to the defecation sensory threshold were analyzed. Results: (1) Among the participants, 57 patients (26.6%) had a defecation sensory threshold of more than 90 ​ml. Patients with a threshold > 90 ​ml showed higher scores of defecation dysfunction in the Constipation Scoring System (CSS) score (p=0.003) and higher scores of constipation in the Colorectal-anal Distress Inventory 8 (CRADI-8) score (p=0.002). (2) The defecation sensation threshold positively correlated with the Ap point (r=0.448, p＜0.001), the Bp point (r=0.345, p=0.009), the area of the levator-ani hiatus measured by transvaginal ultrasound (r=0.403, p=0.002), and parity (r=0.355, p=0.007). Conclusions: Patients diagnosed with pelvic organ prolapse commonly experience an increased threshold of defecation sensation. Elevated thresholds were associated with more frequent constipation symptoms. Additionally, the severity of posterior pelvic prolapse positively correlated with the defecation sensory threshold.

Keywords

• Anorectal function
• Defecation sensory threshold
• Pelvic organ prolapse