Sex differences in anorectal angle and perineal descent.

To elucidate whether sex differences have a significant influence on anorectal angle (ARA) and perineal descent (D), female and male asymptomatic volunteers were examined, using cinedefecography. We found ARA generally bigger in male than in female patients. Mean male values resembled those measured in females with anal incompetence. We also found that the spread of normal ARA in male patients was nearly twice that in female patients, suggesting little value of this variable. D, however, is similar in the 2 groups. Our conclusion is that ARA measured in males has no clinical value. D can probably be useful in both male and female patients for preoperative evaluation of corrective surgery.