Gnawing pain at rght upper abd on and off/ after eating.tests all fine.gynae pres me famotidine for a mth and does not have effect. note tat if i sit in a dental chair post, had instant relief. is tat gas? shld i eat antacid with simethicone instead?

Pay attention to your food which causes the pain. Pain in the right upper quadrant after eating often suggests biliary tract problem although gallbladder is normal by ultrasound. The contraction of gallbladder after a high fat meal can cause your symptom and it's called biliary dyskinesia. You can read more info from this link: https://www.verywellhealth.com/biliary-dyskinesia-4797127