As long as we do lots of foreplay and my body is prepared, I don’t have a problem with pain during anal penetration. However, after about four inches of cock in my ass, I get abdominal pain that I can’t get past, no matter how relaxed or aroused I am. We’ve tried changing positions, but no matter what, it’s as if there is a road block. This is frustrating for me, and I know that for my husband, who wants his balls to slap my pussy on the downswing, it has to be downright maddening. I asked a girlfriend who’s into anal if she had ever experienced this, and she says that around the seven inch mark, her guy seems to hit a wall. Is it possible that there is a sharp bend that is preventing full penetration? Is there a technique to get around the discomfort I am experiencing? Swing to the left? Swing to the right?
The first two inches inside the anus is called the anal canal, and the rectum is the area from the anal canal to the colon, which is another five to seven inches. Unlike the vagina, where you’ve got a pretty straight shot from end to end, the rectum is curved. That’s especially important to know when penetrating someone’s ass with anything longer than a finger, and especially with a dildo or vibrator that is firm and inflexible (like one made of hard plastic, clear acrylic, or glass). If you jam something (especially something rock hard) straight inside you can absolutely hit the rectal wall, which does not feel good. As you get more turned on, the rectum expands, and the curves are less pronounced, but they are still present.
So, the “four inch” stopping point you describe could correspond with the first curve of the rectum, when it curves toward the front of the body. Everyone’s internal geography is unique, and it’s possible that your rectum is more curvy than others. I’ve heard people report similar feelings of facing a roadblock inside their asses.
You’ve already tried changing positions, which would be my first suggestion. I suggest that you pick a long, very flexible toy, and, while masturbating, begin exploring your ass with it. Take note of the curve of the rectum, what feels good and what doesn’t, and if you can find your roadblock, or if you develop discomfort. Experiment with moving the toy forward or back inside of you to see if that changes anything. If you can find the trouble spot, see if you can move past it or around it, again, by moving it toward the front of the body or toward the back. If you are still experiencing problems, I suggest you talk to your doctor about it and have a rectal exam.