When so many things seem to be going wrong... one needs
to step back and analyze things.

For example...did the burning in your pelvic area become worse after the laparoscopies/surgeries?

Do you have edema at all...swelling of the face/neck?
Difficulty breathing? Difficulty bending over, or bending arms and legs?

Has your doctor done autoimmune testing? For lupus or other autoimmune markers? Testing for elevated blood proteins?

Do certain foods make the intestinal thing worse? Spices, peppers, etc? Sometimes keeping a log of what you eat at each meal, what activities you do, etc may show triggers.
Gluten intolerance is a huge masquerader and can affect lots of areas with painful symptoms. Other intolerances too, can be confusing. Sometimes with other foods like nightshades or lily family (onions/garlic), there are thresholds you can have, where one day is okay, but several days in a row, will give you symptoms. When this happens it is difficult to pin down, the culprits.

Have you been tested for Candida? This can cause burning all over. Have you tried thiamine or the newer form, benfotiamine?
If that works for you, then Candida is a possibility.