I know this may sound gross. Know your stool. Ex mucus may indicate crohns, pale color could be meds or bile. Keep a diary. Not just of food but also poop.
How are you doing now? My symptoms sound very similar to yours. I am a 26 year-old female. Constant RUQ pain. I've had nearly every test except ERCP. I am nauseous virtually all the time and often regurgitate food, even hours after eating. I have had 2 ultrasounds that were negative except for a polyp in my gallbladder. No stones according to the radiologist. I've also had 2 HIDA scans, both with 90% ejection fraction. I don't want to lose my gallbladder if it's not the problem. But if it is, I want it gone. I have seen multiple GI speacialists and I have an appt scheduled with a surgeon to get his opinion. Getting desperate for a solution.
Although 47% isn't exactly criteria for removal of a gallbladder by most standards, my surgeon said if mine was functioning around 47% or even a little higher he would have still taken mine out. Turned out mine is functioning at 17% and I am scheduled for surgery on Tuesday. I wonder if your symptoms aren't coming from your gallbladder functioning at 47%? I was told 33% is the magic number for surgery though. I have polyps in my gallbladder as well. I have not lost weight though. I have trouble eating any food too with similar symptoms as yours. I would get another opinion from a different doctor just to be certain esp. if your current doctor is not taking you seriously. I was referred to a surgeon for an opinion after my doctor gave me her opinion. Obviously something is wrong and needs to be addressed.