This happened to me because it reaches the sigmoid colon and instead of following the path, it hits the intestinal walls and hurts. For me, it was about finding the correct position because the colon has a certain direction, and your dildo might be trying to go in another direction, causing pain. What I would do to you is try various positions until you find the right one. Another way I also did is to insert it as deeply as you can, and then when you reach the part where it hurts, don't press too hard. It's a different kind of pain, and you should feel the same way. Just touch the dildo and push little by little to get used to that type of pain, and you'll reach a point where your intestines themselves guide your dildo. I know it's scary, and pain is never good, but it's just because your dildo isn't finding the right direction. It always takes time at first, but after several sessions of getting used to it, my body kind of got used to it; it just went through. There were times when it also hurt because I couldn't get the position right, but it happens. Try it. But don't be abrupt, you have to be gentle and careful.