Anal sex can exacerbate
hemorrhoids and therefore result in bleeding; in other cases, the formation of a hemorrhoid is attributed to anal sex.
[3][93] If bleeding occurs as a result of anal sex, it may also be because of a tear in the anal or rectal tissues (an
anal fissure) or
perforation(a hole) in the
colon, the latter of which being a serious medical issue that should be remedied by immediate medical attention.
[3][93] Because of the rectum's lack of elasticity, the anal
mucous membrane being thin, and small
blood vessels being present directly beneath the mucous membrane, tiny tears and bleeding in the rectum usually result from penetrative anal sex, though the bleeding is usually minor and therefore usually not visible.
[16] By contrast to other anal sexual behaviors, anal fisting poses a more serious danger of damage due to the deliberate stretching of the anal and rectal tissues; anal fisting injuries include anal sphincter lacerations and rectal and
sigmoid colon (rectosigmoid) perforation, which might result in death.
[5][94]
Repetitive penetrative anal sex may result in the anal sphincters becoming weakened, which may cause
rectal prolapse or affect the ability to hold in feces (a condition known as
fecal incontinence).
[3][93] Rectal prolapse is relatively uncommon, however, especially in men, and its causes are not well understood.
[95][96] Kegel exercises have been used to strengthen the anal sphincters and overall
pelvic floor, and may help prevent or remedy fecal incontinence.
[3][97]
