Objective
Rectovaginal endometriosis has the potential to infiltrate into the rectal wall. The recognition of infiltration prior to surgery is of utmost importance since only infiltrative disease should be treated by partial or complete rectal resection. This study compares different imaging procedures in rectovaginal endometriosis cases in an everyday clinical setting.

Methods
Seventy nine consecutive women diagnosed with rectovaginal endometriosis were included in this prospective study. Preoperatively, all women had a rectovaginal gynaecological examination and transvaginal sonography. Furthermore, MRI or rectal endosonography imaging procedures together with a rectosigmoidoscopy and estimation of a serum Ca125 were undertaken. Sensitivity and specificity of all diagnostic tools were compared with the intraoperative findings.

Results
The procedure with the highest accuracy was bimanual rectovaginal gynaecological examination (sensitivity: 0.92/specificity: 0.32). Rectal endosonography obtained a sensitivity of 0.44 and a specificity of 0.77. All other diagnostic procedures such as Ca125 (sensitivity: 0.42/specificity: 0.81), MRI (sensitivity: 0.41/specificity: 0.83), transvaginal sonography (sensitivity: 0.2/ specificity: 0.79) and rectosigmoidoscopy (sensitivity: 0.03/specificity: 0.92) were only of limited value.

Conclusion
The diagnostic method with the highest sensitivity to detect bowel infiltration in an everyday clinical setting is the gynaecological examination. It is followed by rectal endosonography. However, none of the currently available preoperative diagnostic tools can predict infiltrative growth of rectovaginal endometriosis with any certainty. Hence, infiltrative growth still needs to be verified by operative assessment.