Answered on Quora.
Absolutely! How common it is, I am not sure. I’ve been researching this for years though because it fascinates me. You will see references all over the web saying that this is a myth. A published study attempted to answer the question and came up somewhat affirmatively, but the study just led to more arguments.
This man certainly did. His name is Joseph Scambria.
Scambria was a very sexually active gay man for only about 10 years. He contracted a number of STD’s in his anus, which among other things apparently led to a lot of anal scarring. Due to anal sex, he also developed hemorrhoids which became large and inflamed. Soon they protruded externally, and later he developed an anal prolapse.
All of this was from straight up anal sex (although a lot of it with countless partners) over a 10 year period. Finally he was vomiting blood and bleeding anally. He was in hospital care for four months. He dripped blood when he walked around the hospital and lost control of his bowels before he could make it to the bathroom sometimes.
Due to the scarring, he had multiple surgeries on his anus, and a section of it had to be removed. His sphincters were stitched into a narrow channel, but the stitches soon broke. Somehow or other this left him somewhat incontinent, and at the age of 30, he was already in diapers. Two gay male commenters on his site, one 41 and the other 61, both said they have to wear diapers now due to decades of anal sex.
Scambria notes that the bodybuilders he knew wore diapers when they lifted because the strain could cause incontinence.
So on that site, there are three older gay men in diapers from anal sex and some bodybuilders wearing them part-time for the same reason.
Obviously this is a potential but possibly uncommon outcome from a decade or decades of very frequent anal sex.
Scambria also said that he spent a lot of time in the protologist’s office due to anal complaints before he became incontinent. He said that many gay men in San Francisco went to proctologists for one reason or another. He often saw his friends at the office.
He also said that quite a few gay men bottom for 10–20 years and then develop some sort of anal issues, so they quit bottoming and switch to being mostly tops.
The question is how often this happens. There are many reports of gay men who have been having anal sex for decades with few to no problems.
This can also occur with women who have a lot of anal sex, but my perception is that anal incontinence in women from anal sex is much less common than in gay men.
That said, for a gay man to get this, you might have to have a lot of anal sex for 10–40 years with many partners, get multiple anal STD’s, develop terrible hemorrhoids or a prolapse, and get a lot of warning signs before this happens to you.
This issue of anal sex and incontinence in gay men is covered up and handwaved away or out and out denied by a PC media and gay community. As chronic anal incontinence is an outcome for at least a few gay men, I think this issue should get a lot more publicity and research.