Thank you for your query.
It appears both your sons contracted an infection from eating out at the restaurant. It is good that vomitings and loose motions have stopped. It shall take some time for your younger son to return to his usual self following this episoded of gastroenteritis
and his stool to return back to normal. You can give him some probiotic
preparations to normalize his intestines. You can also increase the intake of curd/yougurt and keep him well hydrated.
I hope I have answered your query to your satisfaction.
Wishing your son an early recovery.
Rajiv K Khandelwal