At least 10% of US respondents interviewed on study have practiced it at least once in the previous year. Surprisingly perhaps, among heterosexual women aged 25-29, 12.5% reported having had anal intercourse in the last year, and 2.4% reported having had anal sex during their least sexual encounter.

Another university study shows that 18% of sexually-experienced women and 17% of sexually experienced men have practiced heterosexual anal intercourse. Of these, 69% of the males and 49% of the females reported having anal sex in the previous year, and 26% of males and 17% of females within the previous month.

Clearly anal sex is far more prevalent among adults than previously realized. What reasons can account for this increase in activity? And what are the implications for STDs and safe sex?

To answer the second question first, in a study where heterosexual adults who practiced anal intercourse were interviewed, 60% of them reported not using condoms during sex, and 16% said they always use them. Statistics also show that adults who engage in anal sex are more likely to have a history of STDs or HIV infection.

In general, sexual practices have not necessarily become more experimental or less taboo in recent years, but social attitudes and media saturation covering sexual issues have both changed. For example, after the Monica Lewinsky scandal, in which the whole world learned about President Clinton's opinion that oral sex did not count as "sexual relations," there started to be a more open attitude about oral sex, and perhaps a greater social acceptance of it. For many years, oral sex was actually illegal in a number of states! Some studies suggest that teenagers started practicing oral sex far more often and in greater numbers after the Clnton-Lewinsky affair. It is also true that as kids start engaging in sex at younger ages, more of them become more sexually sophisticated. Oral sex is more pleasure oriented, especially for girls, than intercourse. It also does not carry the risk of pregnancy. And some kids who have pledged to keep their virginity under guidence from religious groups, still engage in oral sex thinking it "doesn't count."

Some of the above is true for teens and anal sex; it does not carry a risk of pregnancy, and (for some odd reason) it is not counted against those trying to keep their virginity. Studies show anal sex is gaining greater popularity among young adults. A survey carried out in Canada showed that, among first year college students, 21.3% of the men and 8.6% of the women had had more than 10 partners, and of these, 26.9% of the men and 34.8% (!!!) of the women practiced anal intercourse. Could it be that young women are pressured by adolescent males to have sex, and to prevent pregnancy they capitulate to having anal intercourse over vaginal intercourse? Perhaps some young women choose anal sex over performing oral sex on their partners because it is a more passive activity.

If you are wanting to try anal sex, or perhaps engage in it more frequently, or if your partner is interested in trying it, there are a few tips to keep in mind. Most important is to practice safe sex. The lining of the anus is made of tissue that is thinner and more fragile than vaginal tissue. This makes it more permeable to infections and more susceptible to tears or fissures, which can also increase the risk of contracting HIV or other STDs. In addition to AIDS you can also get herpes, gonorrhea, syphilis, chlamydia or warts through anal sex, to name a few.

Using lubrication is absolutely necessary. The anus is not self-lubricating like the vagina. You know the drill: petroleum-based lubes break down latex, so you need to use water-based ones like Astroglide or KY jelly. Keep plenty of lube nearby just in case you need more. If you use toys, you can use lube with them, too, but be sure to clean them thoroughly each time after use, so they are ready to go.

First-time anal sex can be difficult and painful, as the anus does not naturally expand to admit anything larger than a bowel movement, normally. So an erect penis can seem like an awfully big object to have in there! You can prepare yourself and partner for this by starting with smaller objects. Fingers are good; make sure hands are scrupulously clean and wear latex gloves with lube. Keep fingernails trimmed, too. You could also use butt plugs or small-sized dildos (again, cleanliness and protection are recommended). There are sex toys made specifically for anal play; check out your favorite sex shop or website and don't be afraid to ask for advice.

Some women experience some anxiety when having anal sex for the first few times. This is natural as it is an unusual sensation, and because it is taboo to so many of us. Some couples find it useful for the women to do a bit of anal play with her male partner so he understands what she is going through. You can use your fingers or a butt plug or dildo for this. You may find you want to add this sort of anal play to your activity because your partner enjoys it too!

This should seem obvious, but it is helpful to have a bowel movement not too long before attempting anal sex. Maintaining a healthy, high-fiber diet can help keep this passage clean and healthy. Apples, celery and fresh pineapple are known for helping keep the bowels squeaky clean. Don't force bowel movements for the sake of sex; this can cause hemorrhoids or tears. You can purchase a simple enema at the drug store for use beforehand, but this can cause liquid to remain in the anus so be prepared for that. A safe bet is to use the enema at least 3 or 4 hours beforehand. If you encounter fecal matter during anal play, stop what you're doing and resume at a better time. Bathing or washing up with soap and water (not just towelettes) after a bowel movement is also recommended before sex play, to prevent any possibility of infection (fecal material entering the vagina can cause vaginal infections). If you decide to extend your anal play to include oral, anal contact, again, be scrupulously clean!

Anal sex, for some couples, is an enjoyable way to be intimate that allows couples new sensations and lets them move beyond "the usual." Follow these tips for safe, clean fun and you can add this activity to your repertoire with confidence.