Anal sphincter structure and function in homosexual males engaging in anoreceptive intercourse.

OBJECTIVES: To evaluate the structure and function of the internal (IAS) and external (EAS) anal sphincters in anoreceptive homosexual men and to determine whether anoreceptive intercourse (ARI) is associated with a higher risk of incontinence in this population.

METHODS: We studied 14 anoreceptive homosexual males and 10 age-matched non-anoreceptive heterosexual males in a controlled, prospective cohort study. Subjects underwent evaluation of resting and maximum squeeze anal canal pressures (maximum squeeze pressure obtained over resting pressure) by station pull-through technique, using a manometric perfusion catheter followed by endoanal ultrasonography to evaluate the structure of the IAS and EAS. Manometry also was performed in age-matched male controls. All subjects completed a questionnaire that assessed sexual practices and bowel habits, including fecal incontinence.

RESULTS: Resting pressures were significantly lower in subjects engaging in ARI (70.7 +/- 3.2 mm Hg vs. 91.4 +/- 5.2 mm Hg; mean +/- SEM, p < 0.003), whereas there was no significant difference in the mean maximum squeeze pressures, compared with controls (177.1 +/- 14.1 mm Hg vs. 151.8 +/- 19.6 mm Hg; mean +/- SEM, p = 0.32). No disruptions of the IAS or EAS were identified in either the anoreceptive or control group. Anoreceptive men tended to have thinner anal sphincters than controls, but the difference was not statistically significant. Furthermore, there were no complaints of fecal incontinence by the study subjects.

CONCLUSIONS: Passive ARI is associated with decreased resting anal canal pressures, but total pressures are normal. There were no IAS or EAS defects, as well as no fecal incontinence, in our subjects. Better relaxation of the ARI subjects during anal canal manometry may explain the lower resting pressures.