Hi, Thanks for posting your query. With the available described details, there appears to high possibility of Acute viral gastroenteritis. You should consult with internal medicine specialist/ gastroenterologist/ pediatrician and should go for thorough check up. He should go for complete blood count, erythrocyte sedimentation rate, ultrasound imaging, and serum electrolytes, renal function test. He should take antispasmodics, probiotics, antipyretics, if needed. Frequent watery diarrhea and vomiting may cause weakness due to loss potassium. You should maintain his hydration status by taking potassium rich liquids. You should take medical advice and with controlled status, you can take flight. Take soft diet along with yogurt and banana. Avoid milk and all milk related products. Take care, Dr. Mayank Bhargava