Purpose: This study was designed to test the reproducibility of the diagnostic assessment of defecographies in patients with a suspected disorder of defecation.
Methods: To evaluate interobserver agreement, 100 defecographic series of patients with complaints suggesting a disordered defecation were evaluated independently by three observers with a standardized questionnaire. After six weeks, a random sample of 35 of 100 defecographies was evaluated a second time with clinical data provided (history, proctologic examination). To evaluate whether the position of residual volume in the rectum would affect agreement, patients with substantial retention either in the upper or lower rectum were also evaluated separately.
Results: Total agreement regarding rectocele and internal prolapse was 0.81 and 0.75, respectively (1.0 = complete agreement), and was significantly higher than chance agreement. Total agreement regarding residual volume in the rectum at the end of defecography and clinical relevance of findings was not different from chance agreement, providing clinical data did not significantly improve agreement. When residual volume was situated in the lower rectum, agreement regarding incompleteness of emptying and its clinical relevance was much better (0.93).
Conclusions: Interobserver agreement is good regarding the deformation of the rectum during defecography but not different from chance agreement regarding the completeness of evacuation.