This study is the first published assessment of the effect of anoreceptive intercourse (ARI) on anal sphincter tone and function. Forty anoreceptive (AR) male homosexuals were compared with 18 age matched non-anoreceptive (non-AR) heterosexual males. Subjects were questioned about ARI, defaecation and faecal incontinence. Anal resting pressure, maximum voluntary squeeze pressure, anal mucosal electrosensitivity, perineal descent and rectal sensation were measured in all subjects. Fourteen of the AR subjects but only one of the non-AR subjects had symptoms of frequent anal incontinence (P < 0.05). There was a significant reduction in both maximum anal resting pressure (P < 0.01) and anal mucosal electrosensitivity (P < 0.05) and a significant difference in the anal resting pressure profile (P = 0.02) in the AR subjects compared with the non-AR subjects. There was a significant reduction in maximum squeeze pressure in AR subjects with anal incontinence compared with either AR subjects without anal incontinence (P < 0.01) or non-AR subjects (P < 0.01). There were no significant differences in stoll consistency, frequency of defaecation, perineal descent or rectal sensation between the groups. ARI is associated with reduced resting pressure in the anal canal and an increased risk of anal incontinence. The risk of incontinence is greatest amongst AR subjects with reduced maximum squeeze pressure.