Frequent indigestion, sour stomach, and nausea after eating light meals. Gallbladder, liver, & pancreas tests normal. Occasional discomfort right side?

Other tests. Other possibilities could include gluten and lactose intolerance, gastritis which a gastroscopy will diagnosis. Also sludge in the gall bladder may not be visible on ultrasound and could cause these symptoms. If you haven't seen one yet, a gastroenterologist is best qualified to continue your evaluation.