Thanks for posting your query.
Stomach ache and diarrhea
suggest gastroentritis. usually it is viral but it can be bacterial. Diarrhea can lead to dehydration
and cause dizziness
, so rehydrate yourself adequately with fluid and electrolyte (OHS). take soft and light diet,eat food in small amounts and let your stomach recover. Do not take more fruit juices.Get lots of rest.
If symptoms persist then contact your doctor, get stool analysis.
Hope it helps.