I Am On Holiday In Dubai And I Got Ill

I am on holiday in Dubai and I got ill at my hotel. I was sick 6 times and had diarrhoea about 30 times in 24 hrs. I complained to the hotel and they said they would like a stool sample tested. I managed a now solid stool sample as this being 40hrs after the first instance. The stool sample came back no wbc or wbc and no ova or parasites. The doctors report said I have acute gastroenteritis and gave me some salt replacement and pills to stop being sick which I already had. The hotel said that they have no case to answer as the stool sample was negative though the doctor said it was positively food poisoning. I never left the hotel during this time. Can I have food poisoning with stool sample being negative 24hrs later? Thanks