Thank you for your query on Healthcare Magic.
Your child is having gastroenteritis
mostly due to a virus or bacteria.
Loose motions will take some time to subside.
And the mainstay of treatment is to maintain hydration of the child by giving sips of oral rehydration solutions like Pedialyte.
The blood test is done to look for Typhoid fever
The test is negative in your child and it is not suggestive of salmonella infection
Continue the medication as advised by your Pediatrician
Hope I have answered your query.