Hello
You mentioned that shortly after the meal , you develop cramps in stomach ( terrible cramps ) , the possibilities of such
nausea , pain and cramps may be due to these reasons , these inslude:
1 Hyper acidity , as this is most common cause .
2 Food
poisoning , this is another most common cause ( although you didn't have
diarrhea but some times TOXIC food of low titers causes only nausea and cramps .
3 Over eating may caused such symptoms .
Anyhow , now , pain and cramps are there , so take
antacid ( if it contains oxetacina , better 0 4 tsf at once ( OTC product) .
If symptoms are severe , you amy need
pantoprazole -d one or two tablet .
Also take one drotavine tablet .
If all available as an OTC , good , if not take prescription from a physician .
As all these symptoms are related to food , so no need of any tests .
If symptoms don't subside after 1-2 days then consult a doctor and deal accordingly.
Good luck.