Purpose: This study was designed to determine if evacuation proctography provides a clinically acceptable estimate of the time and completeness of rectal evacuation.
Methods: Rectodynamics, using a weight transducer and chart recorder to quantify the weight and rate of contrast expelled, was combined with evacuation proctography to assess agreement between the evacuation times recorded and the weight of contrast expelled compared with the lateral area change on proctography.
Results: Mean difference of evacuation times measured by the techniques was 0.1 seconds and the standard deviation of the differences was 1.9 seconds with 95 percent agreement limits of +/- 3.9 seconds. The mean difference between the percentage of contrast evacuated by weight and the change in rectal area on proctography was 4.3 percent. The standard deviation of the differences was 11.9 percent with 95 percent agreement limits of -19.5 percent and +28.1 percent.
Conclusion: Evacuation proctography provides a valid estimation of the time and completeness of rectal evacuation.