My Son 11 Y Age Weight 58kg Fever Starts 5

My son 11 y age weight 58kg
Fever starts 5 days before 1st day temp was 38"c with mild abdomen pain
Than gradgually rises up to 41
We went to ER and they did his blood tests
Cbc normal limits
Malaria negative
Creatine within normal limits
Widal only s. Paratyphy A(o) 1:80
Others all negative
Ultrasound abdomen done fatty liver becaue he is healthy and over weight
Kidneys and spleen normal
Gall bladder contracted

Physican started cefixime 400mg once day for 12 days
And paracetamol 500mg
After 3rd dose of suprax his temp comes normal but still he has mild
Pain
In abdomen motion and aome
Time he vomits
Can you tell me the exact diagnosis
And if he is getting medicine is ok or not
Abdominal cramps and
Motion due to
Medicine or something else

If i should chamge antibiotics which one is better to less drug effects