The only problem I have heard friends complain about is, after several years of taking on anyone and anything, developing an annoying anal itch that is the result of anal warts. Most often, but not always, genital warts are caused by the human papillomavirus. (see
Genital wart - Wikipedia, the free encyclopedia). Anal warts develop on the interior surface skin of the rectum. The virus is passed from someone infected with venereal warts. Although a person may be infected, they may not display or suffer from gential warts, themselves. But genital warts are most often found around the base of the glans penis
in both circumcised and uncircumcised men, or women with venereal warts on the vaginal wall just past the labia minora. Venereal/genital warts can also show up in the corners of a person's mouth and cheeks (for those into cock-worshipping blow jobs). This is the same wart virus that women are susceptible to when having unprotected sex and/or not being vaccinated against vaginal warts (which has only recently become preventable due a major breakthrough in women's health). Both men and women who are not infected benefit from having the vaccination; even though there are other varieties of genital warts.
The usual treatment for those men and women who already have vaginal or rectal warts is to have the warts frozen; a procedure that often requires several visits to a proctologist (for males) or OBGYN (if you're female). After each medical search and destroy mission, most patients are given a big handful of oxycontin, hydrocodone, etc., to dull the week or longer lingering pain before the next appointment. And often, venereal warts return even though an individual has been successfully treated.
I've had a couple of sex partners complain about hemorrhoids. But it's rare for someone to develop hemorrhoids just from anal sex. There are other factors that are the main causes of hemorrhoids. Depending upon the personal view of your proctologist, bottoming can exacerbate or eventually eliminate hemorrhoids. Minor hemorrhoids will break open during anal sex, thus relieving the pressure of the varicose vein, which is basically all a hemorrhoid is. This usually means dealing with a certain amount of post sex bleeding and something not to be terribly alarmed about, unless you produce blood every time you take it in the butt.
It doesn't matter if your sex partner is well-endowed or not.
One known issue is when a top doesn't know what the fuck he (or she) is doing, ramming themselves too forcefully and causing small tears in the interior lining of the anus. If not allowed to heal completely, these tears can develop into fissures and, eventually, a fistula. a fistula requires medical treatment (surgery) for a bunch of reasons. The worst experience I've been witness to was when a room mate developed a 40 C fever and passed out. We took him to the local hospital where the emergency room folks quickly diagnosed sepses. He eventually recovered after having a fistula removed and the wall of his anus stitched back to "normal." He was a very sick puppy for about a six weeks.
Therefore, it's incumbent upon a bottom to practice being a bottom by using butt plugs and indulging in safe butt play/stimulation. (my opinion)
When I first met The Squeeze, he'd bottomed plenty of times before, but not with someone as large as me. After about six months of letting him fuck me, me pleasuring his furry butt with one, then two, then three+ fingers, my tongue, he decided when he wanted to "try me on for size." I worked hard at maintaining a semi-hard erection so his first experiences of me being inside of him were as if he was pleasuring himself with a big, spongy, soft dildo. After a few months he was riding me like a seasoned cowboy.
Yeah, you'll need to take precautions, but by all means be safe.
