Hello, Curiousinoz, You state that you have had reflux in the past. Unless you have been treated with effective medications to control acidity in the stomach, the condition can come back to give you symptoms. I see you took only probiotics. These are effective in controlling bowel symptoms such as Irritable Bowel Syndrome. They help to put back good bacteria in the colon reducing symptoms. For acid control, you need drugs such as proton pump inhibitors which are very highly effective. They are now available over the counter. To name a few, Omeprazole, Pantoprazole, Esomeprazole, Rabeprazole etc. Your symptoms do suggest gastroesophageal reflux disease. I am glad that you are going to undergo upper G.I.Endoscopy. This can give a lot more information about any damage that the lining of the esophagus and stomach present. Doctor can take a biopsy also to look for inflammation and for H.Pylori bacteria which is associated with ulcers. You mention colitis ,but never treated for that. Very mild cases of ulcerative colitis can go into spontaneous remission. You may have had IBS symptoms sometimes confused with colitis. But , colonoscopy and biopsy can give us the answer. Gallbladder problems give a person severe pain on the right side of the abdomen under the rib cage, with some radiation to the back, fevr, chills,nausea,vomiting, and even yellow jaundice. Sonogram of the gallbaldder can show gallstones. Hope this answers your concerns. Discuss these with your doctor. Wish you well.