Purpose: To determine if differences in the viscosity of defecographic contrast media influence radiographic findings.
Materials and methods: Twenty asymptomatic volunteers underwent defecography three times with a different contrast medium used for each examination. The contrast media varied in viscosity from a thin barium liquid to a commercial barium paste formulated for defecography and to an extremely thick, specially prepared barium contrast paste.
Results: Significant differences (P < .05) between media were demonstrated for measurements of the anorectal angle and anorectal junction during liquid medium voiding. Differences in pelvic floor descent and evacuation time were not significant (P > .05). Rectoceles occurred in 14 subjects and were demonstrated with all media. Low-grade intussusceptions were more prevalent with the liquid medium, but their occurrence was not statistically significantly more frequent (P > .05).
Conclusion: Altering the viscosity of the barium contrast medium used for defecography does not substantially affect the subsequent radiographic findings.