Hi ! Good evening. I am Dr Shareef answering your query.
Possibly you have got a either an infection of the intestines from the lunch you had in the school or your intestines are intolerant to some of the components of the food you ate in your lunch. If I were your doctor, I would advise you for a stool test
for ova and cyst
and if positive for it , will prescribe a suitable antibiotic which possibly will relieve you of your symptoms. If you feel that the symptoms occured due to a particular food item, you should start avoiding that component of food in future.
Anyways, you should continue having your high fiber diet and plenty of liquids as advised by your doctor. Till you get investigated, you can go for a anti emetic agent, a proton pump
inhibitor, and a probiotic
to help control your symptoms.
Thanks for using health care magic forum for your health query. Wishing you an early recovery. Dr Shareef.