Every now and then, but if I want anal stimulation while jerking off, I'll use a good-sized buttplug or a penis-shaped vibrator. The buttplug is about 4". I'll put the vibrator in at least 5" but I don't need the vibrator to be on. An orgasm with something in your ass is so much more intense than one without.
Sorry, didn’t notice that the question was for the ladies. However, my statement still holds true. My orgasms are always more intense if I’ve got some kind of anal stimulation. And my wife is no different. When she comes when I have my dick in her ass, her orgasm is 10 times what it is ordinarily. We only do anal when she wants it, because she really has to be in the mood. She still has a little bit of a puritanical concept about getting fucked in the ass but when she’s really looking for that mind-blowing big “O”, anal is the only way to go.