Hi there,
I had similar experiences on progestin based oral birth control. My GYN mentioned that often with prolonged use of this type of pill the body starts bleeding again, and that bleeding will also start if the progestin dose decreases. I found I did much better when I combined a Mirena IUD with a robotic exploratory surgery. (That is, the surgeon inserted the IUD at the end of the procedure while I was still under anesthesia.) I feel that the IUD was effective largely because I had a surgeon who knew to look for and remove endometriosis from OUTSIDE of the uterus as well as on the uterus itself. (After all, a big part of the reason endometriosis is dangerous is because it spreads outside the uterus!) He looked on the lungs, bladder, bowels, peritoneum, SI joint, ureter, etc. We also removed the appendix, as this apparently often helps women with severe endometriosis. Happily, only two tiny 0.5 inch scars. :)
As for the abdominal pain that is akin to bloating, I too dealt with debilitating pain that could be described as such. It was a sad tale that didn't get better with any treatment. However, I have recently felt a huge percent improvement with this since I stopped using toothpaste and mouthwash. I still brush my teeth, just without toothpaste. (Even the 'Natural' stuff from super expensive health stores gave me trouble.) I still gargle, but I mix my own salt water with sea salt. In addition to helping significantly with abdominal and pelvic pain, I also noticed that the spotting which had again started up (even with the IUD) ceased once I cut out these dental products. I have since read the ingredients more carefully on toothpaste and mouthwash... they don't look too friendly. I imagine many of the ingredients have not been studied for long term affects.
And as another little tid-bit in case it's useful: I feel a lot better since I stopped using pre-made sauces and juices. I would imagine that the preservatives and other additives upset the progesterone/estrogen balance. But, now if I want OJ, I just buy some oranges and make my own. If I want marinara, I just buy fresh tomatoes and heat them up with basil, grapeseed oil, and garlic.
That is a very good question. I was on it continuously for 8 yrs came off to bleed for 3 days every 3-4 months when I would spot then go back on it.
What pill are you on?