Vaginal Delivery Is Independently Associated With Internal Hemorrhoids: 169

Introduction: Internal hemorrhoids are common and cause many bothersome symptoms. The cause of symptomatic internal hemorrhoids is not well understood, but associations have been made with chronic constipation and older age. Altered bowel habits and anorectal symptoms are common after pregnancy, but the association between obstetric history and hemorrhoidal disease has not been fully evaluated. We hypothesized that internal hemorrhoids are more common in women with a history of vaginal delivery due to the disruption in anorectal anatomy and defecatory function. Methods: This was a retrospective cohort study of adult female patients who underwent both colonoscopy and high resolution anorectal manometry (HRAM) at a tertiary center in 2013 - 2017. Patient demographics, medication use, obstetric history, and endoscopic and HRAM findings were reviewed. Reports and retroflexed images of the colonoscopy were examined for the presence of internal hemorrhoids. Anorectal physiologic parameters and signs of defecation disorders were identified on HRAM. Univariate analyses were performed using Fisher exact test and student t-test, and logistic regression was used for multivariate analysis. Results: 306 patients (mean age: 57.7±11.1 years) were included. Subjects with hemorrhoids discovered on colonoscopy were significantly older (61.2±12.4 vs 54.8±16.4, p=0.0008) than those without. Hemorrhoids were more prevalent among patients with prior vaginal delivery (50% vs 36.7%, p=0.09), particularly among those reporting constipation symptoms (58.1% vs 37.8%, p=0.038). There were no significant associations between hemorrhoids and any HRAM parameters, including resting tone, squeeze pressure, rectal contraction pressure, and simulated defecation response. Trends toward higher prevalence of dyssynergia and reported constipation symptoms among patients with hemorrhoids were noted on univariate analyses, although statistical significance was not reached. On multivariate analysis controlling for potential confounders, a history of vaginal delivery (OR 2.2, p=0.04), older age (OR 3.3, p=0.002), and constipation symptoms (OR 2.5, p=0.02) were independently associated with increased hemorrhoids. Conclusion: A history of vaginal delivery, older age, and constipation symptoms were independent risk factors for internal hemorrhoids, while dyssynergic defecation and other HRAM parameters were not associated. The pathogenesis of internal hemorrhoids are likely due to more than disrupted defecation alone.