Hi RF, welcome to the forum...
I am so sorry about your experience on the diagnostic rollercoaster and having to deal with doctors acting like 5-year-olds when you are feeling so ill. I know how alienating and nerve-wracking it is to be so incapacitated and not have any answers.
I am going through something eerily similar right now...have had really severe diarrhea for a few years after a couple bouts of intestinal parasitic infections while living abroad. Now am going to the bathroom an average of 15 times/day, extreme weight loss, fevers, electrolyte imbalances, you name it. Have seen two or three GI docs, have had inconclusive test results (some positive, some negative, none definitive), no diagnosis, no real treatment to speak of. They throw around differential diagnoses like Crohn's, celiac, lymphoma, the seemingly most random things. They think it is a small bowel pathology, just like in your case. Small bowel disease is one of the most difficult things to diagnose in medicine. I am a medical student so my docs never cease to remind me of this. Knowing that, unfortunately, doesn't make it any easier.
If you're like me, sometimes you think of just throwing your hands in the air and waiting around to wither away; or you get a burst of energy to "figure it out" and try to enlist as much help as you can; or you just want to scream into a pillow for hours; or you just sit there on the toilet and let it happen...and let it happen again...and again.
I don't live in California so I can't recommend a good doc, but I can recommend some tests that you might ask your next doc about, to see if they might yield more specific answers:
1) Small bowel enteroscopy - goes further into the small intestine than a traditional endoscope, so the jejunum can be partially visualized (normally only the duodenum is).
2) Stool electrolytes (to check osmotic gap)
3) C-reactive protein (CRP), erythro sedimentation rate (ESR), Prometheus IBD serology 7 (all blood tests)
4) Capsule endoscopy
Hang in there. Keep talking to us, we're here to help.