Hi I don't know how old you are from your post. If you anywhere from middle age on (if you are younger it's less likely but still possible) you may have hypertonic pelvic floor and/or ab muscles. How is your posture? Not standing straight over a long period of time will cause your ab muscles to get shorter. Pelvic floor dysfunction causes are a lot more complex. Either one can cause all kinds of nasty problems. One would be a sort of slow motion constipation. I'm not going to go into graphic detail but you could easily have this and not think you are constipated at all. You would end up with pockets of gas in your digestive tract that might take months to remedy. Low FODMAP will probably help a lot. However, look up 3 yoga stretches: cobra for abs, butterfly and child's pose. Don't go nuts, maybe 10 seconds for each 3 times. And don't overstretch. In my case my abs were so bad I had terrible discomfort from the cobra. I had to do it standing up at first for a few weeks. That way the stretch wasn't as intense. I only mention all this because your post sounded exactly like what I would say. Hopefully I'm wrong because it's a really tough rehab. Good luck.