How To Find Specialist with GBP Experience?

 Hello,  I have had many complications since day one.  None of them are life threatening but I am losing too much weight and have pain due to serious constipation.  I dump all the time despite rigidly controlling carbs.  I have a handful of foods that I tolerate well.  I could go on but my main point is that I can't find any docs with experience.  My PCP will refer me to anyone I find.  But I have to find the doc.  I'm really hoping to find someone who has had to go it alone and find help?  My guess is that my vagus nerve was the main problem (I had internal bleeding for 11 days post op) as I have NO sensation of hunger, no appetite at all. Enough.  anyone?  Please.