What can I give for stomach and intestinal pain

My little brother has been saying that he has stomach and intestinal pain for 3 days straight and last night he had a fever that was 100.3 degrees so the only thing that my mom and me have given him is cough medicine because he had a little bit of coughing and Motrin for the fever and pain and he keeps on vomiting and having nausea he says he feels weak and dizzy

Please consult doctor for diagnosis, by that time you can try

Lemon and coconut water: Add 1 teaspoon lemon juice to a cup of coconut water, and make a child to sip this solution every 15 minutes.