Rectal constipation and clinical decision-making: multiple correspondence analysis of defecographic findings

Abstract

The aim of this study was to establish the impact of defecography on the management of patients with chronic constipation. The defecographic series of 581 patients (426 women, 155 men, mean age 51 ± 17 years) with evacuation dysfunctions was reviewed. Proper utilization of defecography was investigated by examining the structural interaction between presenting symptoms using a hierarchical log-linear model analysis. Then, to assess the impact of defecography on clinical decision-making, the multiple correspondence analysis was employed to calculate the relationship between eight radiographic findings (rectal prolapse/intussusception, rectocele, perineal descent, outlet obstruction, barium loss, delayed emptying, residue and rectal enlargement) and six clinical features (fecal blockade, provoked evacuation, tenesmus, feeling of prolapse, incontinence and mucus discharge) which occurred most frequently in the population under study. At the hierarchical log-linear analysis no more than one second-order three-symptom (i.e. fecal blockade, provoked evacuation and mucus discharge) and six first-order two-symptom interactions (including all other symptoms combined in various ways) were obtained, giving no evidence of overutilization of defecography in our constipated group. A close association (inertia, 34.4%) was found at the multiple correspondence analysis between delayed emptying, residue, outlet obstruction and rectal enlargement (relative weight 27.1%, 20.2%, 19.6% and 8.5%, respectively). Our results suggest labeling the first subdimension as the need for a conservative approach, while the second subdimension is surgery. The main value of defecography in chronic constipation is as a simple exploratory method for selecting patients who require admission to biofeedback and pelvic floor re-education.