Gastroparesis is separate from bowel issues/constipation. The only way to get it diagnosed is by a gastric emptying study. you need to see a gastroenterologist. You also need an upper endoscopy to rule out issues in your stomach such as a hernia which is causing the acid reflux etc etc. I wouldn't listen to a dietician - she cannot see inside your stomach nor diagnose you with gastroparesis. Normally with GP you throw up undigested food hours (i mean 6-8 hours or more) after you ate - and the food is pretty much as you ate it hours prior - completely undigested. it is not that common. Again - you need the gastric emptying test to confirm that is what it is - but usually they will start with an upper scope and then move onto the gastric emptying study afterwards.