Hello
As all other tests are normal and no other symptoms , so this type of
bloating and pain in abdomen ( discomfort ) may be due to :
Indigestion or hyper acidity , these are most common cause of such type of symptoms particularly in child of 5 -6 years age.
These measures will be helpful:
1 Try raising the head of your daughter's bed about 4 inches with blocks. It might also help to avoid eating or drinking for 2-3 hours before she lie down. To control stomach acid one should not drinks with caffeine in them or excessive tea or eat chocolates or eat spicy of greasy foods .
Also give her some
antacid but if severe bloating and discomfort she may need drugs like
ranitidine 150 mg on empty stomach.
2 Over eating is another cause of such symptoms , so take care about that also .Fried food , red chillis ( in excess ) also causes such symptoms , so avoid these food items along pizza, burgers, hot dogs .
Hope these measures will be helpful for your daughter.
Good luck.