A new defecographic parameter for assessing rectal emptying

ABSTRACT Purpose: To validate a new defecographic parameter to assess rectal empyting correlating the percentage of weight reduction of barium paste and the variation in the percentage of area reduction of rectum compared before and after defecation during cinedefecography. Method: Thirty-two consecutive female patients with dyschezia who had clinical indication for cinedefecography were selected. Their median age was 58 years old (18–78 years, mean = 55 years). During cinedefecography, we calculated the cross-sectional sagittal area of the rectum before and after defecation and, thus, the percentage of area reduction of the rectum. The percentage of weight reduction of barium paste was calculated after weighing the contrast injected into the rectum and the amount of contrast evacuated, in grams, using a scale. Finally, both percentages were compared and checked for a correlation between them. Pearson's correlation (r) and Student's t test were used for statistical analysis. Results: A correlation between evacuated barium paste and cross-sectional sagittal area of the rectum at the end of defecation was demonstrated (r = 0.668 and p < 0.0001). Conclusion: It is possible to estimate how much barium paste is evacuated based on the variations in cross-sectional sagittal area of the rectum before and after defecation, in cinedefecography