To answer your question more specifically, YES, for about 30 seconds give or take a minute or so. It does stretch out to accommodate the size of the whatever they used to dilate themselves but just as the others have said, unless you are there at the time, you can't tell. It returns to its normal state rather quickly. Don't worry about it.
Anal Sex: What You Need to Know
What Does Anal Sex Feel Like For A Girl? 9 Women Tell Us What Doing It In The Butt Is Really Like
Anal sex gets a bad rap. But I am a warm blooded woman that happens to love anal sex. But even more appalling are the ridiculous articles by women who do love anal sex as a degradation to the female race. I read a twisted article from Vice about why women should only have anal sex. It was all kinds of bat-shit crazy.
What are the risks of anal sex?
If you're curious about anal sex, you're far from alone. It may seem taboo, but behind closed doors, it turns out that more than 1 in 3 women ages 19 to 44 have tried anal sex at least once, according to a survey published in the Journal of Sexual Medicine. That said, it's probably not a regular Saturday night thing. But a few things are clear: Before you try it, it's worth taking time to discuss what to know, what to avoid, and how to prepare for anal sex to make the experience amazing. Here, sex experts share what you need to know if you're interested in trying it out.
Before you dismiss it altogether, you should know that the anus is an erogenous zone and although you may think it's unnatural, that's actually not true. This part of the body has enough nerve endings to rival the vagina and penis. Stimulating the anus correctly can result in just as much pleasure as the genitals. Anatomically speaking, you can have just as intense an orgasm through anal sex as you can through vaginal sex.