Doing the Laparotomy will give your physician a better view of what exactly is going on. This may or may not be Endo, but nevertheless, you should have the Lap done.
Hi there. Wowie! You are going through the ringer!! I'm sure sorry!! Gosh, you've just got a lot going on. Ya know, I'd do what your doctor asks you to do. There could be more uncovered and obviously this is complex. I don't think there will be a simple answer to you. the pain could be endo and you sound like you are in a lot of it. I would have the procedure because I really think you need some answers and this is a way the doctor feels he/she may be able to give them to you.
I would comment on one thing and I'm sure your doctor told you this--- douching is not good for us. It compounds issues and results in things like bacterial infections and yeast overgrowth. So, don't ever douche!
But I feel bad for you and with your allergies to different medications, that makes it really hard. I hope that the procedure yields some answers for you. If you can, come back and let me know how you are and what they say. good luck