I feel nauseated and full all the time. feels like there's a burp or fart that can't go out. abdominal ultrsnd & xrayalways clear. what this could be?

Gastroparesis: There is a condition called gastroparesis where the stomach doesn't empty well and can give symptoms like this. It will often occur in diabetics.

Aerophagia: The two most common problems are air swallowing and bacterial overgrowth in the colon. For the first problem, otc medicines like simethicone, beano, and activated charcoal can help. Peptobismol can decrease odor from gas. For the second, an otc probiotic may help. It is also important to note if any particular food makes it worse--common with lactose intolerance.