I have pain in the same general area that you seem to be having problems with. Although I have not had a HIDA, I have had a chest x-ray and an abdominal ultrasound, which shows everything normal as well. My general practitioner had originally suspected that I have gastritis - I had suspected either an ulcer or gall stones.
I did my first flush this past weekend, and by most measures it was successful; I'm still feeling a bit under the weather though. The pain in my side still comes and goes, and generally feels better after I eat something. It isn't terribly bothersome (yet), just like a dull pressure on my right side. It sometimes feels like it moves down my side, too.
I was just curious if you have had an upper and/or lower GI exam to see if you may a problem somewhere along your intestinal tract. I hope you're feeling better.