Contrast medium gel for marking vaginal position during defecography.

A tampon soaked with contrast medium, which had been inserted into the vagina as part of standard defecography procedure, obscured signs of anterior rectocele and rectal intussusception in a 34-year-old woman. A contrast medium gel for marking vaginal position was formulated, and postsurgical examination with use of the gel revealed improved rectal function and no intussusception. The gel provided excellent contrast without obscuring important diagnostic information.