His gastrointestinal tract got infected due to contaminated food or water.It is Gastro enteritis.
,loose motions are rare.
Rumbling noise is due to intestinal movements.
He should be given antibiotics like Ofloxacin,ornidazole/metronidazole
,antispasmodic like dicyclomine
,Pre and probiotics.Add paracetamol
His symptoms will come down gradually.
Nothing to worry.
Regarding shifting to states,it depends on the response that he is getting here.
Wish him good health and speedy recovery