Thanks for posting your query.
Your child may have acute gastroenteritis
acquired after eating outsource restaurants.
You should consult with pediatrician
and should avoid milk and other milk products.
You should first try to maintain hydration by ORS
liquid as most of the diarrheal cases in children are viral in origin. If his/ her condition won't improve then you should take complete antibiotic course.
Dr. Mayank Bhargava