I have had this dull ache/pain near my lower right ribs for about 7 months now. It seems to be triggered by chocolate or for example pesto pasta. If i avoid these i don't really get the ache however, i can still feel that it is tight in that area when doing stretches after exercise etc. I have had a liver function blood test and an ultrascan (for gallbladder stones), but neither of them showed any abnormalities. This obviously just creates a slight bit of anxiety and i don't know what to do.
Has gastritis been mentioned? An endoscopy identifies it. Avoid your trigger foods and try relaxation techniques. See your doctor again.