Question

In the majority of cases, hydration and bed rest are sufficient treatments for foodborne illnesses.

Answer 1

Here is your answer :
Food Borne illness is due to foreign particles (mainly bacteria) are present in the stomach which cause indigestion, diarrhoea, stomach aches.

So staying hydrated helps as our immune system gets rid of them by removing them from excretion. So if we drink more water i.e. by staying hydrated it helps for passing urine and mainly our feces.

Constant bed rest helps as while we are in sleep out brain does not have to co ordinate for our body movement, our sight etc. So it concentrates more on the healing of our body, and we get healed in faster and better way.

Glad to help!