The Puborectalis and Pegging. What's the Connection?
There is a question that comes up pretty regularly in the various Pegging forum boards I frequent. It typically reads something like this, "When we do Pegging, about 3-4" in, it feels uncomfortable and almost a little painful. What are we doing wrong? Do we need more lube? Thoughts?"
Not the Rectosigmoid Junction
Well, the rectum varies from 6" to 7.5" in length, so at that relatively shallow depth, you are not yet at the back of the rectal canal, bumping up against the rectosigmoid junction. And while lube could certainly be an issue, it's not likely that there is enough lube to penetrate comfortably, then enough of a lack of lube to make it uncomfortable when you are inside the rectum a little ways. Here's the likely culprit...
Blame the Puborectalis!
The puborectalis is a muscle that attaches to the pubic bone, slings around the rectum, and reattaches to the pubic bone. It is a muscle that is contracted when at rest. It's job is to control continence, whenever there is a sudden increase in the pressure of the abdominal cavity. When straining, the muscle contracts, sealing the rectal and vesical necks and thereby preventing fecal or urinary leak. From the perspective of anal penetration, basically it pulls the rectal canal over to the side, creating an angle, which impedes the passage of things through the rectum... like dildos.
Pegging and the Puborectalis
This muscle can come into play during pegging for some receivers, and you don't have to be straining. The sensation is one of vague discomfort, perhaps slightly painful. It occurs shortly after clearing the external sphincter. Sometimes a difficulty in pushing the toy further in can go along with the sensation. Blame the puborectalis! So what can you do?
The Solution
Simple. Bring your knees to your chest. Seriously. This cancels out most of the effect of the puborectalis and allows the rectum to straighten (as shown in the diagram). Voilà! Easier, more comfortable insertion.
This effect is why a company created a small stool called a Squatty Potty that scoots up to your toilet (life hack). Placing your feet on it while having a bowel movement basically puts you in a squatting position - knees to chest. Why is this good? This cancels out the effect of the puborectalis and allows the rectal canal to straighten, which makes it easier for things to go out, and in your rectum!
SO - when engaging in Pegging, if you are past that initial sphincter, the opening of your ass, so to speak, and you are a little ways in and things just don't feel right, or are maybe even a little painful, knees to chest!
More on the Rectosigmoid junction and longer toys here.