Hi thanks for contacting HCM....
You are having complaint if diarrhea , vomiting and mild fever ...
These are not suits in IBS diagnosis. .
You are having infective etiology most likely like 
gastroenteritis or chongitis etc...
Investigate with ....
-USG abdomen 
-stool examination 
If infection seems from above finding antibiotic shot like 
ceftriaxone needed ...
Than oral antibiotic for five days ...
If biliary system infections seems than ERCP like investigation if needed done accordingly....
USG will also rule out if any organic cause present ....
For vomiting take 
domperidone tablet ...
Maintain hydration as having diarrhea ....
Fruit juice more ...
Heavy meal restricted for few days ..
Before giving antibiotic 
widal test done for typhoid ....
If still condition worsen 
endoscopy and biopsy needs to be done .
Advise : physician consultation for preliminary work up 
If needed gastroenterologist consultation 
Take care .....