OBJECTIVE: We developed a protocol to compare the measurements of the anorectal angle in nulliparous and multiparous asymptomatic volunteers in three different situations. SUBJECTS AND METHODS: Defecograms were carried out in 30 women (15 nulliparous and 15 multiparous) from May, 1997 to December, 1998. After rectal administration of texturized barium contrast media, lateral radiographic views of the rectum were obtained at rest, during contraction of the puborectal muscle and during defecation. A repeated measures model was used for the statistical analysis. RESULTS: There were no significant differences between the mean anorectal angles of nulliparous and multiparous volunteers. Measurements were as follows: 92.9° at rest, 78.8° during the contraction of the puborectal muscle and 117.9° during defecation for the nulliparous volunteers; 94.3° at rest, 79.7° during the contraction of the puborectal muscle and 121.4° during defecation for the multiparous volunteers. A significant difference was observed between the anorectal angle measurements at rest, during contraction of the puborectal muscle and during defecation. CONCLUSION: There were no significant differences between the anorectal angle measurements of the two groups of volunteers examined.

Keywords: Defecography, Anus, Rectum, Defecation, Pelvis, Female