Help Me (and My Doctors..) Figure This Out - Digestive Issues?

I am almost 30, female, no children, an artist from home (stress-free!), 5'5", 130 lbs and I exercise a few times a week. I do not ever drink alcohol (hate the taste), and I do not ever smoke or use illegal (or prescribed) recreational drugs.

At age 27, I began having 'hot flashes' where a couple times a month, while sitting comfortably at work or home, I would suddenly feel very hot and my face would flush bright red. People would see it and ask what was wrong haha. After 10 minutes, it would dissipate.

About 6 months after those symptoms began, I began having unexpected bouts of watery stool after eating various meals. As time progressed, these infrequent bouts turned into 'after every meal' bouts, and morning episodes where it felt like my body was flushing something out. I felt poisoned. This continues today, only now I semi control it with Lomotil and Imodium (immodium).

Months later, one eye developed several floaters and now my vision is misty in bright light. Months later, migraines (auras, pain, vomiting) appeared.

7 months ago, I began with pain under my left ribcage that would awaken me from sleep. Then I also had infrequent aches in my lower left abdomen that were weak and would stay a few days and then leave.

Three months ago, lower back pain began out of nowhere that persisted constantly. This past week, that back pain has turned into left sided lower back pulsing pressure when sitting and in some laying positions. It doesn't hurt, it's just very strong throbbing pressure.

I do not have crohns disease, I do not have celiac disease, I do not have parasites, I don't have any tumors based on the imaging tests I've had. I don't have any gall stones. I have had a colonoscopy with biopsies, endoscopy with biopsies, a barium upper GI series and small bowel follow through, lots and lots of blood work, several SIBO tests (all negative). All my blood levels are in good range, all me tests continue to come out negative for any known disease. My gastroenterologist is concerned since I'm so young and have such odd symptoms.

I've tried diet change (low fat, high fat, all veggies, no meat, lots of meat blah blah), I've used Lomotil and Imodium (immodium) somewhat successfully the past two years, cholestyramine was not effective, digestive enzymes are not very helpful, fiber supplements (tried all sorts) are not effective.

If anyone has a clue, please help me!

[Caryopteris]

http://www.immunedisease.com/about-pi/types-of-pi/common-variable-immunodeficiency-cvid.html

I don't know, but maybe something in this group of autoimmune diseases.