Thank you for your query at DoctorSpring.com
With a history of 5 episodes of vomiting, constant nausea, and stomach cramps, it seems more like a stomach bug. In this case you will need your local GP to suggest you appropriate treatment, but tests won't be necessary as of now.
Vomiting can be controlled by Tab. Ondansetron 4 mg, every time before meal, and you can also take Cap. Omeprazole 20 mg once daily before breakfast for 3 days. If there is persistent fever and diarrhea develps then antibiotic such as Ciprofloxacin can be started.
Feel free to discuss further,